01 - Preheat the oven to 350°F. Line the bottom of a 9-inch springform pan with parchment paper.
02 - Beat egg yolks with half the sugar (1.75 oz) until pale and thick. Add melted butter and vanilla, mixing gently. In a separate bowl, whisk egg whites and salt to soft peaks; gradually add remaining sugar and whip to stiff peaks.
03 - Fold almond flour and all-purpose flour into the yolk mixture. Fold in one-third of the egg whites to loosen the batter, then gently fold in the rest until just combined.
04 - Pour batter into the prepared pan. Bake for 18-20 minutes until golden and a toothpick comes out clean. Cool completely in the pan.
05 - If using leaf gelatin, soak in cold water for 5 minutes. Puree raspberries with sugar and lemon juice; strain to remove seeds. Heat 1/3 of the puree gently, add squeezed gelatin (or sprinkle powdered gelatin over and let bloom for 5 minutes, then dissolve), stir until fully melted, then combine with remaining puree. Cool to room temperature.
06 - Whip cold heavy cream to soft peaks. Gently fold cooled raspberry mixture into the whipped cream until smooth and uniform.
07 - Spread raspberry mousse evenly over the cooled almond sponge while still in the springform pan. Smooth the top. Chill for at least 4 hours until fully set.
08 - Carefully remove the cake from the pan. Top with fresh raspberries, dust lightly with powdered sugar, and garnish with mint leaves if desired.