Preheat oven to 325

Mix 2 and 2/3 boxes of muffin mix, 3 eggs, milk, oil, cinnamon and nutmeg together in a large bowl.

Grease pan lightly with cooking spray and flour the pan with pancake mix.

Pour batter in evenly. Put in oven and bake for about 10 minutes (so it starts to set on top)

While the previous step is in the oven, mix solid butter, oats, brown sugar and cinnamon until lumpy. Do not use warm or melted butter.

Take cake from step 4 out and spread oat mixture over top evenly. Continue baking 10-20 minutes, until "smells done".