Preheat the oven according to the cake mix instructions, typically 350°F (175°C). Prepare the cake batter using the ingredients listed on the box, using egg whites if you prefer a lighter-colored cake. Pour the batter into a greased 9×13-inch (23×33 cm) pan and bake according to package directions until set and lightly golden. Remove from the oven and let cool for 10–15 minutes, until the cake is warm but not hot.
1 box vanilla cake mix, Ingredients listed on the box (eggs, oil, water – use egg whites option if desired)
Using the handle of a wooden spoon, poke holes evenly across the surface of the cake, spacing them about 1 inch (2.5 cm) apart and pressing only halfway down into the cake. This allows the filling to settle into the cake while maintaining enough structure for clean slicing.
Place the frozen blueberries in a food processor and blend until mostly smooth. In a large mixing bowl, beat the softened cream cheese until completely smooth and free of lumps. Add the sweetened condensed milk and fresh lemon juice and mix until fully combined and creamy. In a separate bowl, whip the heavy cream to soft–medium peaks. Fold the blueberry purée into the cream cheese mixture, then gently fold in the whipped cream until fully incorporated and smooth. The mixture should be light, creamy, and easily spreadable.
1½ cups (210 g) frozen blueberries, 8 oz (226 g) full-fat cream cheese, 1 can (14 oz / 396 g) sweetened condensed milk, 2 tbsps (30 ml) fresh lemon juice, 1 cup (240 ml) heavy whipping cream
Spoon the blueberry cheesecake filling evenly over the warm cake, using a spatula to guide the mixture into the holes. Spread the remaining filling across the surface in an even layer. Refrigerate the cake for 1 hour to allow the filling to set within the cake.
In a medium saucepan, combine the blueberries, granulated sugar, and lemon juice. Cook over medium heat for 5–7 minutes, stirring occasionally, until the berries release their juices and begin to break down. In a small bowl, whisk together the water and cornstarch to form a slurry, then stir it into the blueberry mixture. Continue cooking for 1–2 minutes, until the mixture thickens and becomes glossy. Remove from the heat and let cool completely to room temperature.
2 cups (280 g) blueberries, ⅓ cup (67 g) granulated sugar, 1 tbsp (15 ml) fresh lemon juice, 2 tbsps (30 ml) water, 1 tbsp (8 g) cornstarch
Once the cheesecake filling has set, gently spread the cooled blueberry compote over the cake in an even layer, taking care not to disturb the layer underneath. The compote should be thick enough to sit on top without soaking into the cake.
Spread the whipped topping evenly over the blueberry layer, smoothing gently to keep the layers distinct. Refrigerate the cake for an additional 2–3 hours, or until fully chilled and set. Slice and serve cold for the best texture.
8 oz (226 g) whipped topping, fresh blueberries