2Cream 1 1/2 cup sugar and unsalted butter in a large bowl until mixture is fluffy and pale yellow, 3 to 5 minutes. Mix 6 egg yolks into the butter mixture, stirring in each one before adding the next. Whisk flour, baking powder, baking soda, and salt in a separate bowl; gradually stir the flour mixture into the egg yolk mixture, alternating with 1 1/2 cup milk, to make a smooth batter. Stir in almond extract.
3Beat 6 egg whites with cream of tartar in a bowl with an electric mixer until frothy; gradually beat in 2 tablespoons sugar until the egg whites form stiff peaks. Gently fold the egg white mixture into the batter, retaining as much volume as possible. Pour the cake batter into prepared baking pan.
