This coffee cake has the most perfect crumble topping… AND it’s lightened up. So the size of your slice (remember, it’s BIG) is totally justifiable.
Vanilla cake mix | Eggs Greek yogurt | Applesauce Mazola corn oil | Cinnamon Water
Flour | Brown sugar Cinnamon | Chilled butter
Powdered sugar | Vanilla | Milk
Using a hand mixer, in a large bowl, mix together cake mix, eggs, yogurt (or extra egg), corn oil, applesauce (or pudding packet), cinnamon and water. Beat until just blended. Pour cake batter into a greased 9x12 pan. Bake at 350˚ for 18-22 minutes or until a toothpick poked through the center comes out clean.
Mix together flour, sugar, brown sugar, cinnamon, and cubed butter using an electric mixer. Beat at a high speed until big crumbles form. Spread out crumbles on a baking sheet. Put the baking sheet in the oven along with the cake, on a different rack. . Bake for 4 minutes then remove from oven and scrape crumbs back into the bowl. Carefully sprinkle cooked crumbles on top of the cake. When done, remove the coffee cake from the oven and let it cool.
Cut cake into 12 squares and serve warm or make ahead the night before and seal with plastic wrap once cooled until morning.
This cooking method takes a little bit extra effort and careful timing but I think it’s worth it.