Preheat oven to 250 degrees F. Mix and sift cake flour, sugar, baking powder, baking soda, and salt into a large bowl.
Add oil, almond extract, 1/3 cup buttermilk, and mashed bananas. Beat for 1 minute with a mixer at low speed.
Add eggs and the remaining buttermilk. Beat for 2 minutes at medium speed.
Fold in chopped nuts, if desired. Pour batter in paper cupcake cups.
Bake for 20 minutes or until a toothpick inserted in the center comes out clean.
Remove cakes from oven and cool for 10 minutes. Frost with the frosting of your choice.