Get out and measure all of your ingredients.
Preheat your oven to 350 degrees.
In a large mixing bowl using a hand mixer (or stand mixer) beat together the butter and sugar until light and fluffy.
In a medium bowl stir together the flour, baking soda and salt.
To the butter and sugar add the egg whites and vanilla.
Alternate adding in the flour mixture and the milk mixture until all combined.
Stir in the Fruity Pebbles or whichever cereal you're using.
Divide the batter between 2 greased 9 inch cake pans.
Bake cakes 25-30 minutes until tooth pick inserted in the middle comes out clean.
Cool in pan for 5 minutes then remove to cooling racks and let cool completely.
Meanwhile prepare your frosting.
In a large bowl with a hand mixer or your stand mixer whip the 4 sticks of butter until fluffy, add in the powdered sugar and mix on low until all combined.
Bump the speed up and whip. Add in the vanilla and milk if your frosting is too thick.
Whip until light and fluffy.
Frost the cooled cake and decorate with more Fruity Pebbles.
Serve and enjoy every bite!