Chocolate Chip Coffee Cake

<ol class="simple-recipe-instructions"> <li itemprop="recipeInstructions">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.</li> <li itemprop="recipeInstructions">Sift the dry ingredients together in a bowl. Set aside. Cream together the butter and sugar. Mix in the egg yolks and vanilla.</li> <li itemprop="recipeInstructions">Add ? of the flour mixture.</li> <li itemprop="recipeInstructions">Add ½ of the sour cream. Mix until combined and repeat until you have added all of the dry ingredients and sour cream.</li> <li itemprop="recipeInstructions">Fold in the beaten egg whites.</li> <li itemprop="recipeInstructions">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.</li> <li itemprop="recipeInstructions">Add the rest of the cake batter, cinnamon sugar mixture, and chocolate chips.</li> <li itemprop="recipeInstructions">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.</li> <li itemprop="recipeInstructions">Look at the layers of chocolate and cinnamony goodness. My oh my.</li> </ol>