The butter is perfect neither too hard nor too soft.
For a single cake, use one springform pan. A regular cake pan is not high enough to contain all the batter.
This step is critical: it is here that air is incorporated into the sugar-butter mixture.
Change the presentation!
Sometimes we like to divide the batter into two 20-cm (8-inch) cake pans to facilitate the assembly of a 2-layer cake. The baking time should be approximately 30 minutes. Between the two layers, you can use whipped cream and fruit to make a shortcake, buttercream to make a birthday cake or pastry cream for a Boston Cream Pie. In this case, glaze the cake with ganache.