Custard Cake with Rhubarb and Strawberries

This custard cake is a little slice of heaven for custard lovers. The combination of custard powder sponge cake and a creamy custard filling is a double whammy of the starring flavour. Team with sweet yet tangy rhubarb compote and fresh strawberries to enjoy a fantastic custard fix in cake form.

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This custard cake is the ideal option for hardcore custard fans who find the opportunities to eat custard lacking in the warmer months of the year. What could be better than incorporating the flavour and colour of this much-loved pudding partner in a cake suitable for all seasons.

Initial recipe testing for this custard layer cake involved making custard from scratch for the creamy filling. However, I felt I was missing a trick. Surely, it was prudent to include the star flavour in the actual sponge cake layers too.

For that reason, I put aside my from-scratch custard notion and instead set to work using a tin of Bird’s custard to create a custard powder sponge cake to pair with the gorgeous custard filling. The result is absolute bliss. Especially for those, like me, who can never quite resist a generous serving of the good stuff when it lands on the table at dessert time.

Why you’ll love this custard powder cake

Should you need further convincing that this custard cake is worth making, consider the following:

• This cake definitely has novelty value, but in chic-vintage style rather than in a childish way.
• The recipe includes 2 layers of custard sponge cake.
• And a sublimely creamy custard filling.
• Both of these elements are delightfully yellow in appearance.
• And it’s up to you what fruity flavours to pair with it – although I obviously recommend going down the rhubarb and custard cake route.
• The cake is large enough to feed 10-12 people.
• It’s very easy to decorate – this cake demands rustic charm rather than elaborate piping skills.

All-in-all, this custard powder cake is quite a unique cake to serve and its flavour is sure to charm all who try it regardless of their age.

What is custard powder?

Bird’s custard powder was created by a Birmingham based chemist, Mr Bird, in 1837 in response to his wife’s allergy to eggs.

It’s a combination of cornflour (corn-starch), colouring and flavouring. When combined with milk and heated, it creates a delicious creamy custard. For sheer ease and authentic custard flavour, Bird’s original custard powder is hard to beat.

If you enjoy cooking with custard powder don’t miss my custard cream biscuits or my custard cream chocolate truffles. They are both fun and delicious recipes sure to delight custard lovers.

Ingredients

There are a few points to note about the ingredients for this 2-layer custard powder cake:

Bird’s Original custard powder: this is the star ingredient in this custard cake and no substitution is advised. It is used in both the sponge cake and the creamy filling.

Plain flour: I prefer to use plain flour and add my own baking powder rather than using self-raising flour. Feel free to use the latter if it’s what you have to hand, but don’t forget to leave out the baking powder if you do.

Butter or baking margarine: either one is acceptable when making the custard sponge cakes in this recipe.

Soured cream: this adds a little extra moistness to the sponge cake. Without it the cake can be a little on the crumbly side due to the inclusion of the custard powder, so don’t leave it out. Plain Greek yoghurt is a good substitute though.

Vanilla extract and vanilla bean paste: I used extract in the custard sponge batter but prefer to use vanilla bean paste for the creamy custard filling because I adore the look of the tiny speckles of vanilla present in the paste. They make the creamy custard filling seem that bit more special. If you only have extract to hand, just use that in both instances.

Double cream: this has a fat content of around 48% and, when whipped, it holds its shape very well, making it ideal for the creamy filling.

Step-by-step instructions

Full instructions and measurements are given in the printable recipe card at the end of this post.

This rhubarb and custard cake is best approached in stages. I suggest making the thick custard for the centre of the cake first as it does need to cool and then chill in the fridge for at least 6 hours.

Make the custard for the creamy custard filling

1. Mix the custard powder and sugar together with ⅓ of the milk until smooth, then pour in the rest of the milk and the vanilla bean paste.
2. Heat gently, stirring constantly with a wooden spoon until the custard begins to thicken.
3. Turn the heat very low and continue to cook until the custard is very thick (keep on stirring).
4. If the custard turns lumpy use a small handheld whisk to beat it until it turns smooth and/ or push it through a fine-meshed sieve.
5. Transfer the custard to a bowl and lay food wrap directly on the surface of the custard to stop skin forming. Let cool then refrigerate for at least 6 hours (or overnight).

Make the rhubarb compote

6. Chop the rhubarb into small pieces about 1cm in length (if your rhubarb is wide also cut in half if it looks too out of proportion to the 1cm length).
7. Put into a large saucepan with the sugar and lemon juice.
8. Cook gently for 12-15 minutes until the fruit is soft and the liquid is thick and jammy. Stir as necessary with a wooden spoon but try not to break the fruit up too much.
9. Set aside to cool.

Make the custard powder sponge cake layers

10. Preheat oven and grease and line two 8-inch circular sandwich tins.
11. Cream butter and sugar together until light and fluffy.
12. Beat in eggs, one at a time.
13. Add vanilla extract and soured cream. Beat again.
14. Mix flour, custard powder and baking powder together then sieve into the cake batter. Fold in using a large metal spoon.
15. Divide between the baking tins and cook for 23-27 minutes until risen, golden and a cocktail stick poked into the centre comes out clean.
16. Let the cakes rest in the tins for 2 minutes then turn out onto a wire rack, remove the parchment and let cool completely.

Assemble the cake

17. Take the chilled custard out of the fridge and beat using electric beaters until a smooth consistency is reached. It will look horribly thick initially (see image below), but once beaten will turn smooth again.
18. Pour in the cream and beat again until combined and the mixture holds its shape (don’t let it get so thick that it will be hard to spread).
19. Put one of the custard sponge cake layers on a plate. Top with just over half of the rhubarb compote then spread around half of the creamy custard filling over it.
20. Top with the second layer of cake and spread the remaining compote over the top (to within 1-2cm of the cake edge). Use the leftover custard cream to pipe rosettes around the edge of the cake then top each one with a small strawberry.

Expert tips

• Preheat the oven and prepare the baking tins before baking commences so that the cake batter gets into the oven to bake as soon as possible (the raising agents are most active when they are freshly mixed, so letting the batter sit around before baking it is a mistake).
• Always grease the tins and use a circle of baking parchment to line the bases regardless of whether or not they are non-stick tins. This is the best way to ensure your cakes never get stuck in the pans.
• Measure your ingredients accurately. It makes all the difference to the success of a cake recipe. Using grams (along with a set of digital scales) is a much more accurate measuring system than cups. For this reason, I do not list cup measurements – sorry.
• Use the tin size specified (two 8-inch round tins). Don’t use tins that are too small or large as bake times will vary, the batter may overflow as it cooks and the thickness of the finished cakes may disappoint.
• Use room temperature butter/ baking margarine. It will be soft and easy to cream with the sugar.
• Don’t be alarmed by the thickness of the custard made for the creamy filling. It will be stiff and gelatinous when cold, and it won’t look appetising. But it mixes up smoothly with electric beaters and goes on to produce the best creamy centre for this cake with a fabulous taste of custard (see the step-by-step images if you’ve happened to miss them – you’ll see what I mean).

Frequently asked questions

Ways to decorate a custard layer cake

• Do like me and turn it into a rhubarb and custard cake using my recipe for quick rhubarb compote (details included below). Alternatively, use rhubarb jam.
• Run entirely with the strawberry theme, using strawberry compote or strawberry jam in place of rhubarb.
• Replace the sticky compotes and jams with fresh fruit – think blackberries, raspberries, strawberries or fresh peaches. Sandwich fruit into the middle of the custard powder cake as well as using some to adorn the top.
• Edible flowers make a great alternative to strawberries for an elegant finishing touch to this cake.
• Ditch the fruit and instead, go for an unadulterated creamy custard sponge cake.
• Make a three-layer custard cake instead (split the cake batter between three 6-inch cake tins instead of two 8-inch cake tins (bake for around 18-22 minutes).

Recipes best served with custard

On the subject of custard, here are a few classic British puddings best served drowning in the golden good stuff.

Have you made this custard powder sponge cake? I hope you enjoyed it. Let me know how you got along by leaving a comment or rating below – it would mean so much to me if you do. You can also show me your creation on Instagram by tagging me @jane_littlesugarsnaps.

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