Preheat your oven to 350 degrees, and grease two 8-inch baking pans with baking spray. Optionally, line the bottoms with parchment paper for easier removal. Set aside.
In a large bowl, beat together the butter, sugar, eggs, sour cream, vanilla extract, almond extract, flour, baking powder, salt, and milk. I know it sounds weird to mix everything at once, but trust me, it works well here. The batter will be thick.
Fold in the sprinkles gently until well distributed. Divide and spread the batter evenly in your two prepared baking pans. Bake for 22-25 minutes, or until a cake tester comes out clean. Cool completely before frosting!
In a large bowl over a double-boiler, stir the egg whites and sugar together until the sugar is well dissolved, and the mixture is about 140-150 degrees. This should take about 5-10 minutes.
Transfer the mixture to a stand mixer, and whip with the whisk attachment on medium speed for 8-10 minutes, or until the mixture has reached stiff peaks, and the outside of the bowl feels completely cool to the touch.
With the mixer running, slowly add the butter about 1 tablespoon at a time until it is completed added. The mixture will go through stages of textures as you continue to beat it, increasing the speed to high after all the butter has been added. It will look thin at first, then will look curdled, but eventually will come together. If you have beaten the frosting for 5-10 minutes, and it still looks curdled, try adding an additional 2 tbs. of butter, and continue beating until light, fluffy, and smooth. Beat in the vanilla and salt.
Frost your cake as desired, and top with more sprinkles. Enjoy!