a. If using round cake pans, using a pastry brush, lightly coat them with softened (not melted) unsalted butter. Then add a little flour and swirl it around—use just enough to ensure that all the butter is lightly coated with flour. Invert the pans and lightly bang on the bottom to remove any excess flour. If you wish, you can line the bottom of the pans with parchment paper cut to fit after buttering. Place it in the bottom and then flour the pan.