Begin by preparing the chocolate sponge cake layer. Preheat oven to 350F and line a 9 or 10-inch spring form pan with parchment paper. Place the eggs, sugar and vanilla into a mixer bowl. Whisk on high speed until egg mixture is thick, pale and ribbons off of whisk. In a separate bowl, combine all the dry ingredients: flour, cocoa powder and baking powder. Sift the dry ingredients into the egg mixture in small batches, folding gently but thoroughly after each addition. Pour the batter into the prepared pan; bake in preheated oven for 18 to 20 minutes, or until the top is completely set.

Remove the cake from the oven and allow it to cool in the pan. Once cooled, use a long serrated knife to split the cake layer in half. Prepare the filling: combine the 1/2 cup blackberry preserves with raspberry liqueur. Spread over one layer of the chocolate sponge cake, then top with the second half. Return the cake back into the spring form pan; set aside.

Prepare the mousse filling. Place cold heavy cream into a mixer bowl and add the 1/2 cup sugar. Whisk on medium speed until soft peaks form. Add the softened whipped cream cheese and whisk on high speed until a smooth and fluffy mixture forms; set aside.

Place 1 cup peaches, sweetened condensed milk and sparkling wine extract into food processor. Puree into a smooth mixture; set aside.

Prepare the gelatin. Sprinkle unflavored gelatin over 1/4 cup champagne. Stir together, then microwave in 10-15 second intervals until the gelatin is completely dissolved. Set aside to cool once the gelatin has dissolved.

Bring everything together. Pour the pureed peach mixture into the whipped cream and fold gently. Add the additional chopped peaches and blackberries; pour in the dissolved gelatin. Fold everything together. Pour the mousse over the chocolate sponge cake layer. Smooth the top with an offset spatula. Refrigerate the cake for at least 6 hours, or best overnight, until completely set.

Prepare the champagne whipped cream once cake has set. Place cold heavy cream, sugar and sparkling wine extract into a mixing bowl. Whisk until a light and fluffy whipped cream forms. Transfer the whipped cream into a pastry bag tipped with a star tip.

To remove the cake from the spring form pan, run a spatula along the edge, then release the form. Transfer onto a cake platter with the help of a flat spatula. Garnish top with whipped cream and fresh blackberries.

Keep cake refrigerated until ready to serve.