Preheat the oven to 350 degrees. Spray two 8" round baking pans with cooking spray. Set aside.
In a medium size bowl, combine all of the ingredients for the cake batter and mix well.
In a separate bowl, combine the topping ingredients and mix until crumbly.
In each baking pan, pour 1/4 of the cake batter. Sprinkle 1/4 of the topping on top of the cake batter for each pan. Then repeat with the remaining cake batter and topping. Each pan should be have four layers: cake batter, topping, cake batter, topping.
Bake the cakes for 30 minutes, until they spring back when you touch the center of them.
Immediately invert the cakes onto a plate and allow them to cool.
While the cakes are cooling, you can make the cream filling. In with a stand mixer or hand-held mixer, beat the two egg whites until they are frothy, about 2-3 minutes. In another bowl beat the butter until it is white in appearance. Add the eggs to the butter, then add the powdered sugar and vanilla. Beat for an additional 2-3 minutes until the cream filling is fluffy. Set aside.
In a small bowl, combine the ingredients for the glaze. The glaze will be thick, but you should still be able to drizzle it on top of the cake. Add more milk if you'd like. Set aside.
To assemble the cake, place one cake on a serving plate. Spread the cream filling on top of the cake. Then place the second cake on top of the cream filling. Drizzle the glaze on top of the cake. You can even top it with nuts if you'd like!