Let butter and egg whites sit at room temperature for 30 minutes.  Preheat oven to 350 degrees.  Prepare two 6 springform pans by spraying the bottom and sides of pan, cover bottom with parchment paper, then spray the top of the paper.

In medium bowl, combine flour, baking powder, baking soda and salt.  Set aside.

In stand mixer, beat the softened butter on high for until creamy (about 30 seconds).  Beat in sugar, vanilla and almond extract until mixed well.  Add in egg whites, one at a time, and beat well.

Add in about a ⅓ of the flour mixture and buttermilk, alternating each addition.  Beat on low speed after each addition just until combined.  Do not overmix.

Spread half of the batter in one prepared pan and the other half in the second springform pan.  Note:  if you only have one springform pan, chill half of the dough until first layer is done and you can use that pan.

Bake cake in preheated oven for 22-26 minutes, until a toothpick inserted in the center comes out clean.

After removing from the oven, place pan on wire rack and cool cake in pan for 10 minutes.  Carefully remove cake from pan and remove paper from bottom of cake.  Place on wire rack for further cooling.

In stand mixer, on high speed, beat softened butter until creamy.  Gradually add in 1 cup powdered sugar and mix on medium speed, beating well.  On slow speed, beat in milk, vanilla and almond extract.  Gradually beat in the rest of powdered sugar on low to medium speed.  You can add in more milk if needed for texture of frosting.

Place one cake layer top side down on cake plate, then frost.  Place second cake layer, bottom side down on top of frosted first layer of cake.  Frost top layer.  Spread frosting over both layers to incorporate two layers together with small spatula.  Serve and enjoy!