Bronte Aurell's saffron roll with almond cream (Saffransrulltarta)

1. Preheat the oven to 200˚C, gas mark 6. Line a baking tray with baking parchment. Using a pencil, draw a 30cm x 25cm rectangle on the parchment, then turn it over. Melt the butter in a small saucepan and set aside to cool slightly before adding the ground saffron to infuse.

2. In a stand mixer with a whisk attachment (or with electric beaters), whisk the eggs and sugar for 6-8 minutes, until the mixture is thick, tripled in volume and leaves a trail for 3 seconds when you raise the whisk. (There is no raising agent in this recipe so getting plenty of air into the mixture at this stage is very important.) Very carefully, pour the melted saffron butter down the side of the mixing bowl, then add the vanilla and fold them in until just combined. Sift over the flour and, using a figure-of-eight motion, carefully fold it in by hand with a spatula or spoon until fully incorporated. Take your time here; if you knock out the air, the cake will not rise properly.

3. Pour the batter onto the baking parchment – it should be thick enough to hold its shape – and allow it to go about 1cm outside the traced edge. Bake for 10 minutes or until soft and springy to the touch. Meanwhile, lay a damp, clean tea towel on the work surface with a sheet of baking parchment the same size as the tea towel on top. Dust with caster sugar.

4. Remove the cake from the oven, trim the edges to the lines on the parchment, then carefully turn it out onto the caster sugar on the parchment-topped tea towel. Remove the top layer of parchment. Roll up the warm cake carefully, lengthways, using the damp tea towel to help you – this will help it retain its shape. Leave wrapped until completely cool.

5. For the filling, mix the ground almonds with the sugars and 1 tbsp water until it forms a paste. Add the custard until you have a thick, spreadable mixture. Whip the cream separately with the vanilla into soft peaks. Unroll the cooled cake. Spread the almond layer across the base, then follow with a layer of whipped cream. Scatter over the blueberries (if using). Roll the cake back up carefully, wrap in the baking parchment again and chill for a few hours before serving. Pipe some rosettes of the remaining cream over the top if liked, decorate with the flaked almonds and dust with icing sugar. It will keep in the fridge for up to 3 days.