Preheat the oven to 165°C (325°F) and line three 15 cm (6 inch) cake pans with parchment paper.

In a bowl, sift together the flour, cornstarch, baking powder, baking soda, and salt.

In another bowl, beat the softened butter, powdered sugar, and lemon zest with an electric mixer on medium speed until creamy.

Add the eggs and vanilla extract, mixing until smooth.

Gradually mix in the buttermilk and lemon juice with the dry ingredients to make a smooth batter.

Divide the batter evenly among the cake pans.

Bake for 30 minutes or until golden. A toothpick inserted in the center should come out clean.

Let the cakes cool in the pans briefly, then transfer them onto a wire rack to cool completely.

Prepare the homemade strawberry compote and let it cool.

Make the Strawberry Swiss Buttercream according to the recipe.

Prepare the Lemon Mascarpone Chantilly following its recipe.

If needed, level the cake layers. Place the first layer on a turntable and pipe a border of strawberry buttercream around the edge. Fill the center with strawberry compote and lemon mascarpone chantilly. Repeat this with the second and third layers.

Apply a crumb coat with the buttercream, then chill the cake in the fridge for at least 2 hours or 30 minutes in the freezer.

Melt the white chocolate with the heavy cream over a double boiler. Stir in the lemon curd and yellow food coloring, then cool the glaze to 30°C (86°F).

Pour the cooled lemon glaze over the chilled cake, allowing it to drip down the sides. Decorate with leftover buttercream and lemon slices.

Let the cake sit at room temperature for 20-30 minutes before serving.