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Vegan Lemon Drizzle Traybake: A Bright 20cm Cake

Bristol Crumb · Updated 2026-07-19 · 7 min read
Vegan Lemon Drizzle Traybake: A Bright 20cm Cake
The gistFor a 20cm vegan lemon drizzle traybake, whisk 250g plain flour, 160g caster sugar, 8g baking powder, 2g bicarbonate of soda, 2g salt, and the zest of 2 lemons. Add 240ml unsweetened soya milk, 80ml neutral oil, and 30ml lemon juice. Bake at 180°C/160°C fan for 30–36 minutes. Prick the hot cake and spoon over a drizzle of 60g sugar mixed with 45ml lemon juice.
Contents

Lemon in the crumb and on the roof

A proper lemon drizzle cake should taste bright before the topping arrives. This one puts zest and measured juice in the batter, then sends a second sharper mixture through the warm surface. The crumb stays soft; the top develops a fine sugary crust; and two lemons finally receive a workload commensurate with their confidence.

The recipe uses a 20cm square tin. Tin area matters: a 20cm square has 400 square centimetres of surface, while a 23cm square has 529—about 32% more. The larger tin would spread this batter thinner and require a different bake time.

Recipe at a glance

At the low end, 20 + 30 + 5 + 15 + 45 = 115 minutes, or 1 hour 55. At the high end, 20 + 36 + 5 + 15 + 45 = 121 minutes, or 2 hours 1 minute.

Ingredients for the cake

Ingredients for the drizzle

You need roughly two to three lemons in total, depending on size and juiciness. Count only as a shopping estimate. The recipe operates on 75ml measured juice: 30ml in the batter + 45ml in the drizzle.

Check sugar, plant milk, and other packaged ingredients for vegan suitability and allergen statements. Vegan does not guarantee milk-, egg-, soya-, nut-, or gluten-free production.

Prepare the lemons and tin

Heat the oven to 180°C conventional or 160°C fan. Lightly grease the tin and line the base and two opposite sides with one parchment strip, leaving handles for lifting later.

Wash and dry the lemons. Zest only the yellow outer layer; the white pith beneath tastes bitter. Juice into a separate cup, strain out seeds, and measure 30ml and 45ml into different containers. Do not pour by eye directly over the bowl. Lemons are not calibrated laboratory equipment, despite the excellent packaging.

Set the 45ml drizzle portion aside. Keep it away from flour dust and raw batter utensils because it will not be cooked.

Combine zest with sugar

Place 160g caster sugar and the lemon zest in a large bowl. Rub them together with clean fingertips for about 30 seconds, until the sugar feels slightly damp and smells strongly of lemon. This releases aromatic oils from the zest.

Add 250g flour, 8g baking powder, 2g bicarbonate, and 2g salt. Whisk thoroughly for 30 seconds so the raising agents disperse.

The Food Standards Agency advises not eating uncooked flour or batter because flour may contain food-poisoning bacteria. Avoid tasting and clean floury hands, bowls, counters, and utensils after mixing.

Mix the batter briefly

Make a well in the dry ingredients. Add 240ml soya milk, 80ml oil, and the measured 30ml lemon juice. Whisk slowly from the centre until almost smooth, about 30 seconds.

Scrape the base and sides, then fold five or six times with a spatula until no dry flour remains. The batter should pour in a thick ribbon. Do not continue beating once uniform; excess mixing develops gluten and can produce a tight or gummy crumb.

Pour into the prepared tin, spread into the corners, and level the surface. Transfer to the oven immediately because acid and bicarbonate are already reacting.

Bake for 30 to 36 minutes

Bake on the centre rack without opening the door for the first 27 minutes. Begin checking at 30 minutes.

The centre should spring back lightly and a fine skewer should emerge with a few moist crumbs but no liquid batter. If wet, bake another 3 minutes, then check in 2- to 3-minute intervals up to about 36 minutes.

If the top colours early, place a loose sheet of foil over it only after the structure is set, handling the hot oven safely. A deeply browned top paired with a wet middle suggests the oven runs hot or the tin is too small.

Do not use colour alone; lemon cake can remain pale even when baked.

Mix and add the drizzle

During the final 5 minutes of baking, stir 60g caster sugar with 45ml lemon juice. The sugar will partly dissolve but should retain some crystals for the crust.

Set the baked tin on a heatproof rack. Use a clean skewer to make holes across the surface, stopping before you reach the tin base. Spoon the drizzle evenly over the hot cake in three passes, allowing each pass to soak before the next.

Use all the measured drizzle. Do not pour a pool into the centre, where it can create one wet patch while the corners conduct a very dry meeting.

The drizzle uses a 4:3 ratio: 60g sugar to 45ml juice. Dividing both numbers by 15 gives 4g sugar for every 3ml juice.

Cool before lifting

Leave the drizzled cake in the tin for 15 minutes. Lift it using parchment handles and place on a rack, keeping the parchment underneath until the cake firms.

Cool at least 45 minutes more before cutting. The sugar crust sets and the crumb finishes stabilising during this period. A warm slice may compress or seem gummy even when the bake was correct.

Use a serrated knife with gentle strokes and wipe it between rows for tidy squares. For 16 pieces, cut four rows by four. For 12, cut three by four; nobody needs a protractor near cake.

A lighter drizzle variation

For a less sugary finish, mix 40g caster sugar with 30ml lemon juice. This keeps the same 4:3 ratio because 40 ÷ 10 = 4 and 30 ÷ 10 = 3.

The smaller batch supplies two-thirds of the original: 40 ÷ 60 = 0.667, and 30 ÷ 45 = 0.667. Apply it in two passes. It will make a thinner crust and slightly less moisture at the top but does not change the cake batter or bake time.

Do not reduce only sugar while retaining all 45ml juice unless you specifically want a wetter, sharper surface.

Plant-milk and oil choices

Unsweetened soya milk provides a dependable crumb. Unsweetened oat milk can replace the full 240ml, though sweetness and texture vary by brand. Avoid strongly flavoured or sweetened products unless that change is intentional.

Use a neutral liquid oil such as rapeseed or sunflower. Extra-virgin olive oil can taste prominent beside lemon; that may be pleasant, but it makes a different cake. Melted coconut oil can re-solidify when it meets cool ingredients, so it is not the easiest direct substitute.

Check every label for the eater. The Food Standards Agency distinguishes vegan claims from allergen free-from claims, because cross-contact with milk, egg, or other allergens can still occur.

Troubleshoot the traybake

Gummy middle: Underbaking, overmixing, too much liquid, or cutting warm are common causes. Measure all liquids, verify oven temperature, and cool for the full hour.

Bitter taste: Too much bicarbonate or grated white pith may be responsible. Weigh 2g bicarbonate and zest lightly.

Dense cake: Raising agents may be old, poorly distributed, or left reacting in the bowl too long. Test baking powder freshness according to its manufacturer and bake promptly.

Drizzle stayed in puddles: The cake may have cooled before application, holes may be too sparse, or the liquid was poured at once. Spoon it over the hot cake in passes.

Top stuck to storage lid: The cake was wrapped before fully cool or the drizzle remained very wet. Cool uncovered on the rack before sealing.

Cake crumbled on lifting: It may have been moved too soon, underbaked, or lifted without parchment support. Wait 15 minutes and use both handles evenly.

What not to substitute casually

A gluten-free flour blend is not a guaranteed 250g direct replacement. Different blends contain starches, proteins, and gums that absorb liquid and set differently. Use a version tested around the exact blend.

Do not add a flax egg “for extra binding” without reducing liquid and testing structure. This cake's flour, starch, and raising system were designed without it. Our vegan egg-substitute guide explains why replacements should be chosen by job rather than added as a general badge of seriousness.

For chocolate, use the one-bowl vegan chocolate cake, which has a different liquid and cocoa balance. For a loaf, vegan banana bread uses fruit weight to control moisture.

Store and freeze

Cool completely, then store airtight in a cool room for up to 3 days as a quality guideline. The sugary drizzle helps retain surface moisture but does not preserve the cake indefinitely. Refrigerate in hot, humid conditions or when a topping's label requires it.

Freeze individual pieces for up to 2 months for best quality. Place parchment between them, wrap airtight, label, and thaw covered at room temperature. The crust may soften slightly after freezing.

Do not leave cut cake exposed; its generous surface area is exceptionally efficient at becoming stale.

This recipe provides general food-preparation information. Follow current food-safety guidance, ingredient labels, and appliance instructions. Vegan does not mean allergen-free. Never eat raw flour, dough, or batter unless specifically labelled ready to eat, and seek qualified advice for individual dietary or health needs.

FAQ

Why use both baking powder and bicarbonate?

Baking powder supplies its own acid-and-base system, while the 2g bicarbonate also reacts with acidity from lemon juice. The combination lifts this egg-free batter without requiring a large amount of either. Weigh both separately and do not confuse bicarbonate of soda with baking powder; swapping their quantities produces a very different cake.

Can I use bottled lemon juice?

Fresh juice gives the cleanest flavour and provides zest, but bottled lemon juice can replace the measured 30ml in the batter and 45ml in the drizzle. Check that it is plain juice, not a sweetened drink. Keep the exact volumes; adding an enthusiastic extra squeeze can alter crumb and drizzle texture.

Why did the middle turn gummy?

The centre may be underbaked, the cake may have been cut warm, or the batter may have been overmixed after flour was hydrated. Verify oven temperature, bake until a skewer has only a few moist crumbs, and let the cake cool fully before slicing. Measure plant milk and oil rather than pouring by eye.

Can I reduce the drizzle sugar?

Yes. For a sharper, lighter finish, mix 40g caster sugar with 30ml lemon juice. That is a separate 4:3 ratio by weight-to-volume, compared with the original 60g to 45ml; both simplify to the same proportion. The smaller batch covers less heavily but does not change the cake batter.

Can I make the traybake gluten-free?

Not by changing only the flour. Gluten-free blends differ in starch, protein, gums, and liquid absorption, so a direct 250g swap may give a gummy or fragile result. Use a tested gluten-free version and check every ingredient and workspace for the eater's needs. Vegan does not mean gluten-free or allergen-free.

How long does lemon drizzle cake keep?

Cool it completely, then store airtight in a cool room for up to 3 days as a quality guideline. The sugary drizzle helps the surface stay moist but does not make the cake shelf-stable indefinitely. Freeze individual well-wrapped slices for up to 2 months and thaw covered at room temperature.