In the bowl of the mixer, whip the egg whites until they are stiff. Take out of the bowl and set aside. I really need another bowl for my mixer.

Sift the dry ingredients together in a bowl. Set aside. Cream together the butter and sugar. Mix in the egg yolks and vanilla.

Add 1/3 of the flour mixture.

Add 1/2 of the sour cream. Mix until combined and repeat until you have added all of the dry ingredients and sour cream.

Fold in the beaten egg whites.

Spread half of the cake batter into a greased 9×13 pan. Sprinkle with the half of the cinnamon and sugar and half of the chocolate chips.

Add the rest of the cake batter, cinnamon sugar mixture, and chocolate chips.

Bake in a preheated 350 degree oven for 40 to 50 minutes. When the cake is done, a tester will come out clean. Cool on a cooling rack.

Look at the layers of chocolate and cinnamony goodness. My oh my.