1Pre-heat oven to 180°C / 160°C fan. Grease and line a deep 20cm (8 inch) round cake tin with parchment paper.
2Using an electric mixer, cream together the butter and sugar until pale, 2-3 minutes.
3While beating, add the eggs one at a time, fully mixing in the one and scraping the sides of the bowl before adding the next one. Add the almond extract with the last egg.
4Whisk together the dry ingredients in a small bowl then add this to the butter and egg mixture. Mix just until combined.
5Finally, add the milk and mix just until combined.
6Spoon half of the batter into the prepared baking tin and smooth the top with a spatula or back of a spoon.
7Scatter half of the berries over the batter then spoon over the remaining cake batter, again, smoothing the top. Scatter over the remaining berries, pressing them lightly into the batter.
8Bake in the pre-heated oven for 50 minutes, then loosely cover with tinfoil and continue to bake until a skewer inserted in the middle comes out without any raw batter, 40-45 minutes.
9Remove the tinfoil and leave to cool in the cake tin on a wire rack for at least 30 minutes, then remove from the cake tin, peeling away the parchment paper from the sides, and leave to cool completely (this can take up to 3 hours).
10For the purée, place the berries in a bowl and mash with a fork (alternatively, blitz in a food processor). Pass the mashed berries through a sieve using the back of a spoon to press through as much of the juice as possible into a small saucepan. Add the sugar and squeeze of lemon to the berry juice then cook over medium heat, stirring often, until reduced by half.
11Remove from heat and leave to cool completely.
12To serve the cake, whip the double cream with icing sugar in a large bowl until firm peaks. Drizzle over the half of the purée and fold through with a large spoon or spatula leaving streaks of white & red. Transfer the cake to a serving plate then top with mounds of the berry rippled cream. Decorate with more berries then serve slices with extra berries and a drizzle of purée.
For the cake
1 ½ (125g) punnets raspberries
1 ½ (125g) punnets blackberries
225g unsalted butter, softened
For the berry purée