Sprinkled gelatin powder over cold water. Set aside and allow to thicken.
Place white chocolate in a heat-proof bowl.
In a separate bowl, whisk together egg yolks and granulated sugar.
Gradually bring ¾ cup of the heavy cream to a simmer.
Slowly pour the hot cream into the yolks/sugar mixture, whisking constantly while pouring.
Pour the mixture back into the saucepan and heat gently. Stir continuously until it thickens (approximately 170° F). Remove from heat and add the dissolved gelatin. Mix until gelatin melts.
Pour the hot cream/egg mixture over the white chocolate. Let rest for a few minutes then stir until smooth. Allow mixture to cool for 15 - 20 minutes prior to adding the whipped cream in the next step.
Whip 2 cups of heavy cream to medium peaks. Whisk ¼ of the cream into the white chocolate mixture, then gently fold in remaining whipped cream.
Assemble the Cake:
Place one layer of the vanilla cake in the bottom of a 9" springform pan.
Pour ½ cup of the raspberry preserves over the vanilla cake layer and spread evenly using an offset spatula.
Place raspberries on top of the raspberry preserves.
Pour ½ of the White Chocolate Mousse over the raspberries. Tap the pan lightly on the countertop to release any trapped air bubbles.
Place second layer of vanilla cake on top of the white chocolate mousse. Press down gently.
Pour ½ cup of the raspberry preserves over the vanilla cake layer and spread evenly using an offset spatula.
Pour the remaining ½ of the White Chocolate Mousse over the raspberries. Tap the pan lightly on the countertop to release any trapped air bubbles.
Place cake in refrigerator until set (approximately 2 hours).
Unmold the cake and place on a serving platter.
Video
Notes
Any leftover mousse may be frozen for up to two months - or make white chocolate parfaits with berries.