Preheat your oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing them with unsalted butter or cooking spray.

In a large mixing bowl, whisk together the all-purpose flour, baking powder, and salt until well combined.

Cream the unsalted butter and granulated sugar together until light and fluffy, then beat in the eggs one at a time, followed by vanilla extract.

Gradually add the flour mixture to the butter mixture, alternating with whole milk, until just smooth.

Divide the cake batter evenly between the prepared pans and bake for 25-30 minutes.

Allow the cakes to cool in the pans for about 10 minutes, then turn them out onto a wire rack to cool completely.

Slice each cooled cake layer horizontally in half to create four layers.

In a saucepan, warm the whole milk, then whisk together sugar, cornstarch, and egg yolks. Slowly pour the heated milk into the egg mixture and cook until the custard thickens.

Assemble the cake by spreading custard and diced strawberries between the layers, finishing with custard on top and garnishing with strawberries.

Cover the cake and chill in the refrigerator for 1-2 hours before serving.