Preheat your oven to 350°F (175°C). Grease two 9-inch round cake pans with unsalted butter and dust with flour.

In a large mixing bowl, combine the all-purpose flour, baking powder, and salt. Whisk together thoroughly.

Use an electric mixer to cream together the softened unsalted butter and granulated sugar until light and fluffy, about 3-5 minutes. Gradually add the eggs and vanilla extract, mixing until incorporated.

Alternately add the dry mixture and whole milk to the butter mixture, starting with dry ingredients. Mix until smooth; the batter should be thick yet pourable.

Divide the batter evenly between the two prepared pans and bake for 25-30 minutes. Check for doneness by inserting a toothpick in the center.

Cool the cakes in the pans for about 10 minutes, then transfer to wire racks to cool completely.

For the custard, combine whole milk, sugar, and cornstarch in a saucepan over medium heat. In a separate bowl, whisk the egg yolks, then temper them with the hot milk mixture before returning to the saucepan.

Cook the custard, stirring constantly, until it thickens and bubbles, approximately 5-7 minutes.

Once cakes are cool, slice each layer in half horizontally to create four layers. Layer the first cake on a serving platter with custard and sliced strawberries.

Stack remaining layers with custard and strawberries, topping the cake with any leftover custard and garnishing with halved strawberries and whipped cream. Chill in the refrigerator for at least 1-2 hours before serving.