1-Preheat your oven to 350°F (175°C) and prepare your baking pan by greasing it lightly and lining with parchment paper to prevent sticking. This step ensures even baking and easy removal later.

2-In a large bowl, sift together the 250 grams of unbleached cake flour, 2 teaspoons of baking powder, and 1/2 teaspoon of salt to ensure even mixing and a light texture that makes the cake airy.

3-Cream the 115 grams of unsalted butter and 200 grams of granulated sugar until light and fluffy for about 3-5 minutes using an electric mixer, which helps incorporate air for a tender crumb.

4-Add the 3 large eggs one at a time, beating well after each addition to incorporate air and ensure a smooth batter that rises nicely in the oven.

5-Gradually fold in the flour mixture along with 60 milliliters of vegetable oil, 2 teaspoons of vanilla extract, and 240 milliliters of whole milk into the wet ingredients, mixing gently to maintain airiness while preventing overmixing.

6-Pour the batter into the prepared pan, smoothing the top with a spatula for even baking, which leads to those perfect fluffy layers we love.

7-Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean, then let it cool completely on a wire rack.

8-While the cake bakes, prepare the berry filling by mixing 200 grams of seedless berry jam with 60 milliliters of water, then stirring in 100 grams each of fresh strawberries, raspberries, and blueberries, along with 1 tablespoon of lemon juice and 1 teaspoon of lemon zest for a fresh, tangy burst.

9-Next, make the Chantilly cream by whipping 240 milliliters of cold heavy whipping cream with 125 grams of mascarpone cheese, 125 grams of cream cheese, 100 grams of powdered sugar, and 1 teaspoon of vanilla extract until soft peaks form.

10-Once cooled, assemble by spreading the berry filling between cake layers and topping with the Chantilly cream. For dietary adaptations, substitute ingredients as noted earlier to keep the process seamless.