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

In a medium bowl, whisk together all-purpose flour, baking powder, and salt. Set aside.

In a large mixing bowl, cream together unsalted butter and granulated sugar until light and fluffy.

Beat in eggs one at a time, then mix in vanilla extract until fully combined.

Alternate adding the flour mixture and milk to the butter mixture, mixing until just combined.

Divide the batter evenly between the prepared pans and bake for 25-30 minutes. Cool in pans for 10 minutes.

Turn out onto a wire rack to cool completely, then slice each layer in half horizontally.

In a saucepan, warm the whole milk until just steaming.

In a bowl, whisk together sugar, cornstarch, and egg yolks. Gradually add the warm milk, whisking constantly.

Return the mixture to the saucepan and cook until thickened, about 5-7 minutes.

To assemble, place one layer of cake on a serving plate. Spread with custard, then top with sliced strawberries. Repeat with remaining layers.

Finish with custard on the top layer and additional strawberries and whipped cream if desired.

Cover with plastic wrap and refrigerate for 1-2 hours before serving.