1-Getting Started: Preheat oven to 175°C (350°F) and line three 20 cm (8-inch) cake pans with parchment paper. Grease the pans with non-stick spray to avoid sticking, which helps the cake release easily after baking.

2-Mixing the Batter: Stir 60 ml (1/4 cup) lemon juice into the whole milk and let it sit for 15 minutes to curdle, creating a tangy base. In a large bowl, rub the zest from 3 large lemons into 400 g (2 cups) granulated sugar to release the oils and boost flavor.

3-Mixing the Batter: Sift 360 g (3 cups) cake flour, 5 g (1 teaspoon) baking soda, 8 g (2 teaspoons) baking powder, and 5 g (1 teaspoon) coarse kosher salt over the sugar mixture, then whisk everything together. In another bowl, whisk the curdled milk with 2 large eggs, 2 large egg whites, 120 ml (1/2 cup) sour cream, 120 ml (1/2 cup) vegetable oil, 5 ml (1 teaspoon) vanilla extract, and the remaining lemon juice until smooth.

4-Baking and Finishing: Add the wet ingredients to the dry ones and mix by hand just until smooth, then divide the batter evenly among the pans. Bake for 25-27 minutes until a toothpick comes out clean and the tops spring back.

5-Baking and Finishing: Let the cakes cool completely in the pans on a wire rack. For the buttercream, beat 230 g (1 cup / 2 sticks) softened unsalted butter with 250 g (1 cup) seedless raspberry jam until smooth, then add 500 g (4 cups) powdered sugar, 5 g (1 teaspoon) meringue powder, 2 g (1/4 teaspoon) coarse kosher salt, and 5 ml (1 teaspoon) vanilla extract. Mix on low, then beat on medium-high for 5 minutes until fluffy.

6-Baking and Finishing: To make the white chocolate rose, melt 200 g (7 oz) white chocolate over a double boiler and spoon it into a rose-shaped silicone mold. Chill until firm, unmold the petals, and assemble them into a rose shape for the topper. Finally, frost the cooled cakes with the buttercream and add the white chocolate rose on top. The total time is about 57 minutes, plus cooling and decorating.