- Sift the flour together with cornstarch and baking powder.
- Melt the butter and white chocolate, stirring. Cool to room temperature.
- Divide the eggs into yolks and whites. Start whipping the yolks with a mixer, pouring sugar in a thin stream. Whip the yolk mixture until fluffy and light.
- Add pistachio paste, and whip for another 1-2 minutes until evenly colored.
- Pour in the melted chocolate and butter, and whip until smooth.
- Whip the egg whites to peaks.
- In three passes, mix in all the flour and whipped whites (first flour, mix the dough with a spatula, then whites, flour, again whites, etc.).
- Preheat the oven to 356F (180C).
- Pour the dough onto a baking sheet, and bake the pistachio sponge for about 20-35 minutes until cooked.
- Cut out the circles, three different sizes for each cup.
Soak the gelatin in water.
Bring the milk to a hot state over medium heat, add white chocolate to it, stir until the chocolate dissolves.
Add gelatin to chocolate milk mixture.
In a separate bowl, whip the cream until fluffy.
Combine the cream and milk mixture, add pistachio paste, and whisk. The mousse is ready.
Fill the cups in such an order: sponge, mousse, sponge, mousse, sponge, mousse. Decorate with chopped pistachios.