Preheat your oven to 350°F (175°C). Mix your sponge cake according to the package instructions or your favorite homemade recipe, ensuring the batter is smooth. Pour the batter into a prepared cake pan and bake for 25–30 minutes, or until the top is golden and a toothpick inserted in the center comes out clean. Allow the cake to cool completely on a wire rack.

While the sponge cake cools, prepare the mousse. In a mixing bowl, whip heavy cream until soft peaks form. In a separate bowl, dissolve gelatin in warm water. Fold the dissolved gelatin and sugar into the whipped cream, along with your choice of flavoring. Mix gently until fully combined.

Once the sponge cake has cooled, slice it into even layers. Place a ring mold on a serving plate and start layering the sponge cake and mousse alternately. Begin with a layer of sponge, followed by mousse, and add a handful of seasonal fruits in between each layer for extra flavor and color. Repeat until all layers are assembled.

Cover the assembled dessert with plastic wrap and refrigerate for at least 4 hours. For best results, chill the White Christmas Charlotte overnight.

When ready to serve, gently run a warm knife around the edges of the mold before removing it. Carefully lift off the mold and garnish the top with additional seasonal fruits and a dusting of powdered sugar. Slice into portions and enjoy.