Texas chocolate sheet cake with chocolate ganache recipe

This is often made with a chocolate fudge topping that’s poured on while still warm, but that produces something more like a pudding than a cake for teatime – so I’ve gone for a chocolate ganache instead. Buttermilk gives a lovely tang.

Timings

Prep time: 20 minutes, plus cooling time
Cook time: 35 minutes

Serves 

16 or more

Ingredients

For the cake

• 175g butter, at room temperature, plus extra for greasing
• 85g cocoa powder
• 2 tbsp brewed espresso
• 250g soft dark-brown sugar
• 185ml buttermilk
• 3 tsp vanilla extract
• 375g caster sugar
• 3 large eggs, beaten
• 300g plain flour
• 1¼ tsp bicarbonate of soda

For the ganache topping

• 150g plain chocolate
• 150g milk chocolate
• 250ml double cream
• chocolate chips, chunks or shavings, to decorate

Method

1. Preheat the oven to 170C/160C fan/gas mark 3½. Butter a baking tin measuring 23 x 33cm and line the base with greaseproof paper.
2. In a large bowl, mix the cocoa, coffee and brown sugar with 325ml boiling water and stir to dissolve. Allow to cool a little then add the buttermilk, mixing until everything is smooth. Add the vanilla.
3. In an electric mixer, cream the butter with the caster sugar until light and fluffy. Add the eggs a little at a time, beating well after each addition.
4. Mix together the flour, bicarbonate of soda and ½ tsp salt. With the mixer on a very low speed, add the dry ingredients a couple of spoonfuls at a time, alternating with the chocolate liquid. Scrape down the sides of the bowl every so often.
5. Pour the batter into the tin and bake for 25-30 minutes, or until a skewer inserted into the middle comes out clean. Leave to cool in the tin, then turn out on to a wire rack.
6. To make the ganache, chop both chocolates and put them in a mixer. Heat the cream until just under boiling, then pour over the chocolate. Leave for 2 minutes, then whisk until the chocolate has melted and the mixture is light, about 2 minutes. Leave to cool for 40 minutes.
7. Spread the ganache over the cake. Sprinkle on the chocolate chips, chunks or shavings. Cut into squares as soon as it’s made, or as needed.