01 - Preheat the oven to 350°F. Grease and line a 9-inch springform pan with parchment paper.
02 - Beat the egg whites with half the sugar until stiff peaks form. Set aside.
03 - Whisk egg yolks with remaining sugar until pale and thick. Add melted butter and vanilla extract, whisking to combine.
04 - Fold almond flour, all-purpose flour, and salt into the yolk mixture until just incorporated.
05 - Gently fold the beaten egg whites into the batter in three additions, being careful not to deflate the mixture.
06 - Pour batter into the prepared pan and bake for 20 to 25 minutes, until golden and a toothpick inserted in the center comes out clean. Cool completely in the pan.
07 - Soak gelatin sheets in cold water for 5 minutes. If using powdered gelatin, bloom in 3 tbsp cold water.
08 - Heat raspberries, sugar, and lemon juice in a saucepan over medium heat until raspberries break down and release their juices, about 5 minutes.
09 - Puree the mixture and strain through a fine mesh sieve to remove seeds. Return the smooth purée to a clean bowl.
10 - Warm 3 tbsp of the raspberry purée and dissolve the bloomed gelatin completely. Stir back into the remaining purée and let cool to room temperature.
11 - Whip cold heavy cream to soft peaks. The cream should hold its shape but still be slightly fluid.
12 - Gently fold the cooled raspberry mixture into the whipped cream until smooth and evenly colored.
13 - Place the cooled almond sponge in the cleaned springform ring. Spread raspberry mousse evenly over the sponge. Use an offset spatula to smooth the top.
14 - Refrigerate the cake for 2 hours, until the mousse is firm and set.
15 - Soak gelatin sheets in cold water for 5 minutes. If using powdered gelatin, bloom in 2 tbsp cold water.
16 - Heat raspberry purée and sugar in a small saucepan until warm and sugar dissolves. Remove from heat and stir in the bloomed gelatin until completely dissolved. Let cool slightly.
17 - Pour the slightly cooled glaze gently over the set mousse layer. Tilt the pan to spread evenly. Refrigerate at least 1 hour until glaze is completely set.
18 - Release the cake from the springform pan and transfer to a serving plate. Garnish with fresh raspberries and mint leaves if desired. Slice and serve chilled.