Boston Cream Trifle

For the custard, heat the milk, cream, and vanilla pod in a saucepan over a medium heat. Bring it to a simmer and remove from the heat immediately.

In a medium bowl, whisk together the yolks, cornflour, caster sugar, and salt. Gradually add the hot milk mixture, whisking constantly. Transfer to clean saucepan and cook over a low heat, stirring constantly, until the custard is thick enough to coat the back of a spoon. Sieve the custard into a bowl to remove the vanilla pod and any lumps. Stir in the butter and vanilla extract. Place a sheet of cling film over the bowl, making sure it touches the top of the custard, and chill.

Preheat the oven to 180°C (Gas 4). Double sift the flour, baking powder, and salt into a bowl and set aside. Using an electric hand whisk, cream together the butter and sugar in a separate bowl until light and fluffy. Add the eggs, one at a time, whisking between additions, then add the vanilla extract. Fold in the flour mixture using a large metal spoon, one-third at a time, alternating with the milk. Continue to fold until the battery is smooth and everything is well incorporated.

Grease and line a 23cm square cake tin and pour the batter into the pan, making sure it spreads evenly. Bake for 25 minutes, or until golden brown and springy to the touch. Remove from the oven and let it cool.

For the ganache, heat the chocolate and cream in a small heatproof bowl over a saucepan of simmering water (see technique for melting chocolate). The bowl should not touch the water. Stir occasionally until the chocolate melts. Remove from the heat and set aside.

Slice the cake into 12 x 12cm squares and place a layer of cake at the bottom of a tall glass bowl. Spread the berries evenly on top of the cake, reserving a handful for garnishing. Pour the custard evenly over the berries, then top with the remaining cake slices. Pour the ganache over the top and smooth it out. Top with the reserved berries and place in the fridge to chill. Serve chilled.