1. Line a (9x5 inch) loaf pan with parchment paper, leaving a 2 inch overhang on both sides. 2. Using a large serrated bread knife, slice the top dome of the cake off to level the top. Then slice the cake horizontally into 3 layers. Don't stress if they're not each the perfect size. Gently fit the bottom piece of cake inside the loaf pan.3. In a bowl, combine the strawberry ice cream and blackberry gelato until swirled/mixed. Don't over mix, you want swirls. Spread half of the ice cream over the bottom piece of cake. Dollop over about 1/4 cup of jam. Add the middle layer of cake, then the remaining ice cream. Dollop over 1/4 cup of jam. Add the top piece of cake, gently press down. Wrap the cake and freeze 4 hours or until frozen. 4. Before serving, using an electric mixer, whip the cream with the vanilla and sugar (if using) until soft peaks form. 5. Remove the cake from the freezer. Use the parchment paper to lift the cake out of the pan, then invert it onto a serving plate. Dollop on the cream, then 1/4 cup of jam. Top with fresh fruit. Slice and enjoy immediately.