Gather Ingredients: Start with basic ingredients—flour, sugar, eggs, butter, milk, vanilla, and chocolate. Fresh and high-quality items will ensure the best results.
Prepare the Sponge Cake: Cream the butter and sugar, then add eggs and sifted flour. Bake in two round pans until golden and springy.
Cool the Cake Layers: Allow the cakes to cool completely on a wire rack to avoid melting the custard when assembled.
Make the Pastry Cream: Heat milk and whisk with egg yolks, sugar, cornstarch, and vanilla. Stir constantly until thick and smooth.
Chill the Pastry Cream: Cover with plastic wrap touching the surface to prevent a skin from forming. Refrigerate until set.
Assemble the Layers: Place one cake layer on a plate, spread the chilled custard evenly, and top with the second layer.
Glaze the Cake: Pour the chocolate glaze over the top layer, letting it drip slightly down the sides for a classic look.
Chill Before Serving: Let the pie set in the refrigerator for at least an hour to firm up and blend flavors.