Best-of-the-best summer swiss roll

Method

1. Heat the oven to 170ºC fan/gas 5. Line the baking tray with baking paper and scatter over the flaked almonds evenly. Sift the flour, baking powder and salt into a bowl and set aside.
2. Crack the eggs into the bowl of a stand mixer with a whisk attached (you could also use an electric hand mixer). Whisk at a medium-high speed for 4 minutes until pale, frothy and doubled in size. Turn the speed down to low, then add the sugar a spoonful at a time. Once the sugar is all incorporated, turn back to high and whisk for 4 more minutes.
3. Stir the milk and oil into the eggs and sugar, then fold in the sifted dry ingredients using a large spatula until evenly mixed. Pour the mixture carefully over the almonds in the tray, gently spread out evenly, then bake for 15-18 minutes. When the sponge is ready, it will have shrunk a little around the edges and should spring back with a gentle prod in the centre. Turn out onto a board and carefully peel off the baking paper. Flip again so it’s almond-side down, then roll up as tightly as you can and leave to cool rolled up.
4. While the sponge cools, make a compote. Roughly chop half the berries, put in a pan with the icing sugar and simmer for about 10 minutes until you have a chunky, glossy sauce. Pour into a sieve set over a bowl and leave to cool, reserving both the syrup that collects in the bowl and the chunkier compote in the sieve.
5. Meanwhile, in a mixing bowl, whip the cream and 2 tbsp icing sugar to the soft peak stage (the tips will flop over when you lift out the beaters), then transfer to another bowl. Add the mascarpone and vanilla extract to the first bowl (there’s no need to clean it out), whip for 2 minutes at a high speed, then fold the cream back in.
6. Now you’re ready to assemble. Unroll the sponge onto a large clean tea towel and spread the strained chunky compote evenly over the top, almost to the edges. Evenly spread over two thirds of the mascarpone cream. Re-roll the sponge as tightly as possible, using the tea towel to gently help the roll as it turns. Chill for at least 1 hour to firm up the cream mixture.
7. Transfer to a serving platter, seam-side down, then spoon over the remaining mascarpone cream and top with the rest of the fresh fruit. Melt the chocolate, either by pulsing it in a microwave or sitting it in a heatproof bowl set over a pan of simmering water (don’t let the water touch the bowl), then transfer to a piping bag (see Know-how). Drizzle the swiss roll with the reserved compote syrup, then use a piping bag to drizzle over the melted chocolate to finish.