Bloom the gelatin: Sprinkle the powdered gelatin over 2 tablespoon of water in a small microwave-safe container. Set it aside to bloom.
Make the crust: Place the graham crackers in a plastic bag and crush them evenly into fine crumbs using a rolling pin or something similar. Transfer the crumbs to a bowl, add the melted butter, and mix well until evenly combined.Line the bottom of a 7-inch cake pan with parchment paper. Spread the graham cracker mixture evenly over the bottom of the pan. Place a piece of plastic wrap over the crumbs, then use the bottom of a flat glass or cup to firmly press and compact the crust. Use the back of a spoon to press the edges as well. Refrigerate while preparing the filling. Prepare the cheesecake filling: Place the softened cream cheese in a bowl. Gradually add the sugar while mixing until smooth and creamy. Add the sour cream and lemon juice, then mix well until fully combined.Add the heavy cream and whisk about 30 times until evenly mixed. For an extra smooth texture, strain the mixture through a fine mesh sieve into another bowl. This step is optional but recommended. Melt the gelatin: Microwave the bloomed gelatin for about 10 seconds at 1200W, or just until fully melted. Do not overheat or boil the gelatin, as overheating may prevent the cheesecake from setting properly.
Combine and chill: Add the melted gelatin to the cheesecake mixture and stir well until evenly combined. Pour the filling over the prepared crust and smooth the surface. Refrigerate for at least 4–5 hours, or until fully set.
Make the blueberry sauce: Add the blueberries, sugar, and lemon juice to a microwave-safe bowl. Gently stir with a spoon to evenly coat the blueberries. Lightly cover with plastic wrap and microwave for about 1 minute, or until the blueberries soften and release their juices. Let it cool completely in the refrigerator.
Serve: Once the cheesecake is fully set, remove it from the pan and top with the chilled blueberry sauce before serving.
