Bumpy Cake

by Barry Lewis

Prep time
180 mins
Bake time
35 mins


Chocolate Cake

50g cocoa powder

120ml brewed coffee, cold

120ml vegetable oil

2 eggs

220ml buttermilk

Pinch of salt

1tsp bicarbonate soda

350g sugar

250g plain flour

For the buttercream bumps

90g butter, softened

Pinch salt

250g icing sugar

1tsp vanilla extract

For the fudge topping

120ml buttermilk

40g treacle

120g butter

50g cocoa powder

Pinch salt

450g icing sugar

A bumpy cake apparently originates from the 1930’s but that’s pretty much all I know after being sent this recipe to try… a couple of things to tell you though, first up it takes a while to make and also you may get chocolate ganache everywhere!

But it’s worth it, it sort of has chilled mocha gateaux vibes with buttercream bumps and ganache holding it all together, truly delicious. I took it to tennis and it was demolished by some other fellow athletes. Want more cake? Head to the baking section of the website for more ideas.

How to make a bumpy cake

Ok first up make the cake, in a bowl combine the buttermilk, eggs. vegetable oil, salt, bicarbonate soda, cocoa and coffee together. Whisk it really well until smooth. Then add in the sugar and flour, really mix well to get a lovely batter for a couple of minutes either by hand or with an electric whisk.

Bake in a lined tin (ideally 9 x 13 inch rectangular) at 350f/Gas5/180C/160fan – make sure your tin is lined high up around the edges with baking parchment to hold in the ganache. Bake for 35 mins, it will spring back when touched, leave to cool fully, then place in freezer to chill whilst you make the buttercream.

For the buttercream, mix the butter with an electric whisk until creamy and fluffy, then add in the salt, icing sugar and vanilla extract. Beat again until light and fluffy, thickened slightly, if it’s too thickened add a tsp or so of milk.

Transfer to a piping back with a large round ½ inch tip on the end. With the cake cold pipe lines of buttercream on top of the cake and leave an inch gap each time. Do them across the shorter side of the cake in long lines. Place the cake in the freezer again to firm up the buttercream bumps!

For the fudge topping, get a saucepan and dollop in the treacle, buttermilk, butter, salt and cocoa powder. Warm over a medium heat stirring constantly to melt through and become glossy and smooth, push it to a gentle simmer, stirring often for 5 mins over a low heat and remove from the heat to cool, whisk in the icing sugar off of the heat until lump free, transfer to a jug, cool until room temperature, but still pourable.

Pour the ganache all over the cake topping covering the buttercream bumps and level off. Chill fully in the fridge / freezer until the ganache topping is set – at least an hour. Slice into wedges to reveal the bumpy lines and share with as many people as possible!

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