Preheat the oven to 350ºF. Lightly grease an 8-inch round cake pan. Set aside.

Melt 4 tablespoons (57g) butter in a small pot over medium heat. Once melted, add ½ cup (100g) light brown sugar. Stir to combine. Cook over medium heat for 3 minutes, stirring occasionally, until the sugar blends into the butter and the mixture darkens slightly in color.

Reduce the heat to low and add 2 tablespoons (30g) heavy cream and 1 teaspoon vanilla extract. Whisk until smooth and simmer for 1 minute. Turn off the heat and stir in the 1½ cups (60g) cornflakes.

Pour the mixture into the prepared cake pan and smooth it into an even layer. Transfer to the freezer for 15 minutes.

Place the fresh blueberries in a bowl with 1 tablespoon (7g) cornstarch and 1 tablespoon (15g) granulated sugar. Stir to coat. Set aside.

Place the freeze-dried blueberries in a plastic storage bag or food processor and crush or pulse until a coarse powder forms. Set aside.

Sift 1 cup (120g) all-purpose flour, 1 tablespoon (7g) powdered buttermilk, 1½ teaspoons baking powder, and ¼ teaspoon kosher salt into a small bowl. Set aside.

Add 4 tablespoons (57g) room-temperature butter and ½ cup (100g) granulated sugar to a large bowl. Use an electric hand mixer to cream them together. Add 1 egg and beat until smooth.

Add half the sifted dry ingredients along with the crushed freeze-dried blueberries and beat with the mixer until just combined. Add ½ cup (120g) whole milk and beat until just combined. Add the remaining dry ingredients along with 1 teaspoon vanilla extract. Beat until just combined. Don’t overmix!

Remove the cake pan from the freezer. Spoon the prepared blueberries over the cornflake caramel and arrange them in an even layer. Pour the batter over the blueberries and smooth it out with the back of the spatula.

Transfer the cake to the oven and bake for 50 to 55 minutes until a toothpick inserted into the center of the cake comes out clean.

Let the cake stand at room temperature for 30 to 45 minutes. The cake should still be warm to the touch.

As the cake cools, make the whipped mascarpone. Add ½ cup (120g) heavy cream, 2 tablespoons (40g) honey, ½ cup (60g) powdered sugar, 1 tablespoon (15g) lemon juice, and 1 teaspoon lemon zest to a large mixing bowl. Beat with an electric hand mixer until thickened with soft peaks nearly beginning to form.

Add 2 ounces (56g) mascarpone cheese and continue beating until stiff peaks form, being careful not to overmix, as the mascarpone can separate when overworked. Refrigerate until needed.

Place a large plate over the cake pan and carefully invert the cake onto the plate.

Slice the cake and pipe or spoon the whipped mascarpone on top. Finish with more lightly crushed freeze-dried blueberries if desired. Enjoy!