Preheat your oven to 350 degrees. Grease a 9x13 pan with butter and set aside.
Combine the butter and brown sugar in the bowl of an electric mixer. Cream until fluffy. Scrape the sides of the bowl and add the vanilla followed by the eggs.
Whisk together the flour, baking powder, 1 teaspoon cinnamon, nutmeg, and salt in a separate bowl.
Slowly stir into your butter mixture until fully combined.
Transfer to your prepared 9x13 pan.
Stir together 1 tablespoon sugar and 1 teaspoon cinnamon. Sprinkle over the top of your dough.
Bake 30-35 minutes or until the center is set and a toothpick comes out clean.
