Preheat your oven to 350°F (175°C).

Grease and flour two 8-inch round cake pans, or line them with parchment paper. This prevents the cake from sticking and ensures it comes out of the pan cleanly.

In a large mixing bowl, use an electric mixer to cream together 1 cup softened unsalted butter and 1 cup granulated sugar. Beat on medium speed until the mixture is light and fluffy, about 3-5 minutes.

Add 4 large eggs one at a time, beating well after each addition. This helps to fully incorporate the eggs into the mixture. Add 1 ½ teaspoons of vanilla extract and mix it in.

In a separate bowl, whisk together 2 ½ cups all-purpose flour, 1 tablespoon baking powder, and ½ teaspoon salt.

Gradually add the dry ingredients to the butter mixture, alternating with 1 cup whole milk. Start and end with the dry ingredients. Mix on low speed until just combined to avoid overmixing, which can make the cake dense.

Divide the batter evenly between the two prepared pans.

Bake in the preheated oven for 25 to 30 minutes. To test for doneness, insert a toothpick into the center of the cakes. If it comes out clean or with just a few crumbs, the cakes are done.

Let the cakes cool in the pans for about 10 minutes, then transfer them to a wire rack to cool completely. This step helps keep the cakes from becoming soggy.

Wash the berries and dry them. Slice larger berries if needed.

In a saucepan, heat the berries with 2-4 tablespoons of sugar and a squeeze of lemon juice over medium heat. Simmer for 5-10 minutes until softened and slightly thickened.

Let the mixture cool completely before using.

Spread the cooled berry mixture between cake layers or on top as desired.

In a large bowl, pour 2 cups heavy cream. Using an electric mixer, whip the cream on medium speed until it starts to thicken.

Add ¼ cup powdered sugar and 1 teaspoon vanilla extract. Continue to whip the cream until it reaches soft peaks. Soft peaks will hold their shape but still have a slight curve at the tip.

Place one layer of the cooled cake on a serving plate or cake stand.

Spread a generous layer of Chantilly cream over the cake. Arrange a mixture of fresh berries (strawberries, blueberries, raspberries) on top of the cream.

Place the second cake layer on top of the berries. Spread more Chantilly cream over the top and sides of the cake. Smooth the cream with a spatula.

Decorate the cake with additional fresh berries for a beautiful and appetizing finish.

Refrigerate the assembled cake for at least 1 hour before serving. This allows the Chantilly cream to set and the flavors to meld together, making the cake easier to slice.