The short answer: multiply every ingredient in your lemon drizzle cake recipe by 2, then fix the three exceptions — leavening (about 1.5× instead of 2×), salt (to taste), and baking time (check early). The full scaled table below uses a standard lemon drizzle cake recipe that serves 4 (one small loaf cake). Scaled, it serves about 8.
All amounts in this guide are approximate, and the recipe below is an example — a standard home-baking lemon drizzle cake recipe — so you can see the scaling worked out in numbers. Your own recipe's amounts will differ; apply the factor 2× to whatever your recipe calls for, and use the leavening, salt and time rules on this page for the exceptions. Flour is weighed at 120 g per cup spooned and levelled (King Arthur Baking), granulated sugar at 200 g per cup, and butter at 227 g per cup. Verify with a kitchen scale when it matters: a scale removes the guesswork that cups always carry.
The scaled recipe, in a table
| Ingredient | Original (serves 4) | Scaled ×2 (serves about 8) | Note |
|---|---|---|---|
| All-purpose flour | 1 1/2 cups (180 g) | 3 cups (360 g) | |
| Granulated sugar | 3/4 cup (150 g) | 1 1/2 cup (300 g) | |
| Unsalted butter, softened | 1/2 cup (114 g) | 1 cup (227 g) | |
| Eggs | 2 | 4 | |
| Baking powder | 1 1/2 tsp | 2 1/4 tsp | scales less than the recipe — about 1.5×, a rule of thumb from the recipe scaler guidance |
| Fine salt | 1/4 tsp | 1/2 tsp | to taste — start here, then adjust |
| Lemon zest | 1 lemon | 2 lemons | |
| Lemon juice | 2 tbsp | 4 tbsp | |
| Granulated sugar, for the drizzle | 1/4 cup (50 g) | 1/2 cup (100 g) |
Read the table from left to right: the middle column is the recipe as written, the next column is the same recipe multiplied by 2, and the note column flags the ingredients that break the rule. The baking powder uses about 1.5× (not 2×). Salt is listed at the scaled amount, but treat it as a starting point and taste before you commit — saltiness depends on the salt you use and the other ingredients, so a flat multiplier is a guess, not a fact.
What does not scale
Leavening
When doubling a recipe, use about 1.5× the baking powder — not 2×. Too much leavening makes the bake rise fast and then collapse, leaving a sunken middle and a soapy or metallic taste. This is the guidance the recipe scaler gives, and it is a rule of thumb, not a sourced figure: leavening does not scale linearly, because the gas it produces escapes faster from a larger batter and the structure cannot hold it. If your lemon drizzle cake has risen and fallen before, too much leavening is the first thing to check.
Salt
Salt scales by feel, not by maths. Multiply it by 2 as a starting point, then taste — a doubling lemon drizzle cake with salt scaled blindly can taste flat and harsh, or dull and under-seasoned, depending on the salt. Fine table salt is saltier by volume than kosher salt, so if you switch salts, adjust again. The place to fix salt is before baking, in the dough or batter: once the bake is in the oven, the salt is set, and no amount of topping will fix it afterwards.
Baking time
Baking time does not scale with the recipe. A doubling lemon drizzle cake bakes at the same temperature, 350°F (175°C) for 40–45 minutes, but the time changes with batter depth and tin size, not with the amount of food. Check doneness 5–10 minutes before the recipe time, and judge by the usual tests — a skewer coming out clean, a top that springs back, edges pulling away from the tin — rather than by the clock. The baking time adjuster will work out a starting point for the new time if you tell it the old time and the new tin size.
Why doubling needs more than a bigger bowl
Doubling is where most scaling mistakes happen, because everything about the recipe changes at once: the bowl is fuller, the tin is bigger, the oven works harder, and the chemistry of the leavening no longer matches the batter. The single most important rule is the leavening rule: when you double a recipe, use about 1.5× the baking powder, baking soda or yeast — not 2×. This is the guidance the recipe scaler gives, and it is a rule of thumb, not a laboratory measurement, but it is the rule that stops a doubled bake from rising fast and then collapsing into a sunken, soapy-tasting middle. Salt is the second exception: scale it as a starting point, then taste and adjust, because doubling salt blindly can make a bake taste flat and harsh.
The third change is the pan. A doubled lemon drizzle cake does not fit in the original tin, and baking it in two batches in the original tin is often the better choice: two identical bakes behave exactly like the original recipe, with the same time and the same result. If you do use one bigger tin, the batter will be deeper, so the middle takes longer to set while the edges keep cooking — check doneness 5–10 minutes before the recipe time and be ready to cover the top loosely with foil if it browns too fast. The pan size converter will tell you which tin holds a doubled batch, and the baking time adjuster gives a starting point for the longer bake.
Worked examples
A recipe that calls for 1 1/2 cups of flour. Scaled, that becomes 3 cups — and if you are weighing, that is 180 g becoming 360 g. Weighing matters most at this scale, because a cup of flour can vary by 20 g or more depending on how you fill it, and a 20 g error is a much bigger share of a halved batch than of the original.
Butter, the ingredient that sets the texture. Your recipe calls for 1/2 cup of butter (114 g); scaled, that is 1 cup (227 g). Butter scales cleanly by the full factor, unlike leavening, so there is nothing to adjust here — just weigh it, because butter is sold by weight and the wrapper markings are approximate.
The drizzle scales with the cake. The original drizzle uses 1/4 cup of granulated sugar (50 g) and 2 tablespoons of lemon juice; scaled by 2×, that becomes 1/2 cup of sugar (100 g) and 4 tbsp of lemon juice. You will need about one lemon per original batch for zest and juice, so a doubled cake needs two lemons and a tripled cake needs three — buy one extra, because lemons vary in how much juice they give.
Lemon drizzle specifics: crumb, drizzle and tin
A lemon drizzle cake lives or dies on its crumb, and the crumb comes from creaming the butter and sugar properly and from the baking powder doing its job — which is why the leavening rule is the most important thing on this page. Cream the butter and sugar until pale and fluffy, about 3–4 minutes with an electric mixer, then add the eggs one at a time, then fold in the flour and baking powder gently. Over-mixing after the flour goes in develops gluten and makes a tough, close crumb instead of a tender one, and that matters more in a doubled or tripled batch, where the mixing takes longer and it is tempting to keep the mixer running.
The drizzle is what makes this cake, and it scales simply: sugar and lemon juice in the same ratio, poured over the hot cake so it soaks in and sets into a crisp, crackly top. Prick the hot cake all over with a skewer before pouring, and pour slowly so the drizzle soaks in rather than running off the sides. A doubled cake needs a bigger tin — two loaf tins are the safest choice, because a single deeper loaf takes much longer to bake through and the drizzle can make a soggy middle if the crumb is underbaked. Check doneness with a skewer 5–10 minutes before the recipe time: it should come out clean, and the top should spring back when pressed lightly.
The most common mistake is scaling the baking powder by the full factor. Doubled baking powder makes the cake rise fast and collapse, leaving a sunken middle and a soapy, metallic taste; use about 1.5× when doubling and about 2× when tripling, as a rule of thumb. The second mistake is using bottled lemon juice instead of fresh — the flavour is flat, and the drizzle will not set the same way. The third is pouring the drizzle over a cold cake, which leaves it sitting on top instead of soaking in; the cake must be hot from the oven. The fourth is opening the oven door in the first 20 minutes, which can make the cake sink.
Eggs double cleanly — two eggs become four — so there is no awkward half-egg problem in this direction. The only thing to watch is size: if your recipe was written with large eggs and you only have medium ones, add an extra egg for every four the recipe calls for, or weigh the eggs. A large egg is about 50 g without the shell, and weighing is the most reliable way to scale eggs in any direction.
A doubled batch needs either two original-size tins or one tin with twice the volume. Two tins are the safer choice: each one bakes exactly like the original, so the time and temperature do not change at all, and you can freeze one batch for later. If you go with one bigger tin, remember that batter depth is what sets the baking time — a deeper batter takes longer, and the top can brown before the middle is done. Tent the tin with foil once the top is golden, and test the middle with a skewer before you call it done.
Storing and making ahead
Lemon drizzle cake keeps for 3–4 days in an airtight container at room temperature, and it actually improves on the second day as the drizzle soaks through the crumb. It freezes well for up to 3 months, wrapped tightly — freeze it before adding the drizzle if you can, then drizzle it fresh after defrosting. Do not refrigerate it; the fridge dries the crumb out and dulls the lemon flavour.
Frequently asked questions
Can I just multiply everything by 2?
Most things, yes — flour, sugar, butter, eggs, milk and flavourings all multiply by the full factor. The exceptions are leavening, which scales at about 1.5× (a rule of thumb), salt, which you should scale as a starting point and then adjust by taste, and baking time, which does not scale at all and must be judged by doneness. If you multiply everything blindly, the most likely failure is a bake that rises and collapses.
How much baking powder do I use when doubling?
Use about 1.5× the original amount, not 2×. For the example recipe on this page, that means 2 1/4 tsp instead of the 3 tsp a straight multiplication would give. This is a rule of thumb from the recipe scaler guidance, not a sourced figure, and it is the single most useful scaling rule there is: too much leavening is the most common reason a scaled bake collapses.
Does the baking time change when I scale from 4 to 8 servings?
Yes, but not by the factor. Baking time changes with batter depth and tin size, so a larger batch in a bigger tin takes longer, and a smaller batch in a smaller tin takes less time — but neither changes in proportion to the recipe. Check doneness 5–10 minutes before the recipe time, use the skewer test, and cover the top with foil if it browns before the middle is set. The baking time adjuster will work out a starting point for the new time.
What size tin do I need for the scaled recipe?
Use the pan size converter and match the volume, not the diameter: a tin's volume grows with the square of its width, so a small increase in diameter is a large increase in volume. Two original-size tins are often the safest choice for a doubled or tripled recipe, because each one then bakes exactly like the original. For a halved recipe, use a tin about half the volume of the original.
How do I know when the scaled cake is done?
Use a skewer, not the clock: push it into the middle of the cake and it should come out clean, and the top should spring back when pressed lightly. Start checking 5–10 minutes before the recipe time, because a scaled cake in a different tin bakes at a different rate. If the top is browning too fast, cover it loosely with foil and keep baking until the middle is set.
Should I scale the salt by the full factor?
Use the scaled amount as a starting point, then taste and adjust. Salt perception depends on the salt you use — fine table salt is saltier by volume than kosher salt — and on the other ingredients, so a flat multiplier is a guess. In sweet baking, a little extra salt sharpens the flavour; too much makes it taste flat and harsh. Taste the dough or batter before baking, and remember you can always add a pinch, but you cannot take salt out.