Preheat your oven to 325°F (160°C). In a mixing bowl, combine the graham cracker crumbs, granulated sugar, and melted butter until well mixed. Press this into a 9-inch springform pan and bake for 10 minutes. Allow to cool.

Beat the softened cream cheese in a mixing bowl until creamy. Gradually add powdered sugar and vanilla extract. Whip heavy cream separately until soft peaks form, then fold into the cream cheese mixture and spread over the cooled crust. Refrigerate for at least 30 minutes.

In a saucepan, heat blueberries, a bit of sugar, and lemon juice for about 10 minutes until thickened. Blend and strain to remove seeds. Bloom gelatin in cold water, then stir into the warm blueberry mixture. Cool to room temperature.

Fold whipped cream into the cooled blueberry mixture. Spread evenly over the cheesecake layer, cover, and refrigerate for at least 4 hours until set.

Once set, warm blueberry preserves and spread over the mousse. Garnish with fresh blueberries and whipped cream before serving chilled.