Raspberry-Strawberry Swirl Snack Cake with Almond Crumb

Steps

1. Make the berry filling first: in a small saucepan, stir the raspberries, strawberries, 30 g of the sugar, the cornstarch and the lemon juice. Simmer over medium heat, stirring, for 6–8 minutes until thick and jammy. Spread on a plate and let cool for 20 minutes.
2. Preheat the oven to 350°F (175°C). Grease a 9x9-inch pan with a little of the butter and line it with parchment.
3. Make the almond crumb: in a bowl, rub 40 g of the flour, 40 g of the sugar, 30 g of the butter and a pinch (about one third) of the salt together until clumpy, then stir in the sliced almonds. Chill until needed.
4. Make the cake batter: whisk the remaining 250 g flour, the baking powder, the baking soda and the remaining salt in a bowl.
5. In a large bowl, beat the remaining butter, the remaining 160 g sugar and the lemon zest for 3 minutes until fluffy. Beat in the eggs one at a time, then the sour cream, milk and vanilla.
6. Fold the flour mixture into the butter mixture just until no dry streaks remain.
7. Spread two thirds of the batter in the pan. Spoon the cooled berry filling over it, then dollop the remaining third of the batter on top and gently swirl with a knife.
8. Scatter the almond crumb evenly over the top.
9. Bake for 45–50 minutes, until golden and a toothpick in the cake (not the berry layer) comes out clean.
10. Cool in the pan on a rack for at least 45 minutes so the filling sets, then lift out and cut into 12 slices.