Banana Layer Cake

Banana Layer Cake
2 1/4 cups cake flour
3/4 teaspoon baking soda
1/2 teaspoon baking powder
1/2 teaspoon plus pinch of salt
1 cup mashed ripe bananas (about 2 large)
1/4 cup buttermilk
1 teaspoon plus 1 tablespoon vanilla extract
1 1/2 cups (3 sticks) unsalted butter, room temperature
1 1/3 cups sugar
2 large eggs

Preheat oven to 350°F. Lightly butter three 8-inch-diameter cake pans with 2-inch-high sides; dust pans with flour. Combine cake flour, baking soda, baking powder and 1/2 teaspoon salt in medium bowl. Mix mashed bananas, buttermilk and 1 teaspoon vanilla in another medium bowl. Using electric mixer, beat 1/2 cup butter and sugar in large bowl until blended. Add eggs 1 at a time, beating to blend after each addition. Add dry ingredients alternately with banana mixture in 3 additions, beginning and ending with dry ingredients and beating just until blended after each addition. Divide batter equally among prepared pans.
Bake cakes until tops are just beginning to color and tester inserted into center comes out with a few crumbs attached, about 20 minutes. Cool cakes in pans on racks 10 minutes. Using small knife, cut around cakes to loosen; turn cakes out onto racks and cool completely.