Cinnamon Nutmeg Coffee Cake

Preheat the oven to 350 degrees F (180 degrees C) with an oven rack set in the center of the oven. Grease a 9-inch square pan with nonstick spray, and line the pan with parchment paper, allowing at least 2 inch of excess on each side (these will act as handles to make for an easier removal later).

Gather all ingredients.

To make the crumble topping: Stir flour, brown sugar, cinnamon, nutmeg, and salt together in a bowl until combined. Add butter and use your hands or a pastry cutter to mix until butter is fully incorporated, and mixture forms moistened clumps. It should no longer appear powdery. Set aside.

To make the coffee cake: Beat butter, sugar, and brown sugar in the bowl of an electric mixer fitted with the paddle attachment on medium speed until light and fluffy, 3 to 4 minutes.

Add eggs, 1 at a time, mixing well on medium speed to incorporate and scraping the bowl well after each addition.

Whisk flour, cinnamon, nutmeg, baking powder, baking soda, and salt together in a bowl to combine. Add about half of the mixture to the mixer and mix on low speed to combine, then scrape the bowl well.

With the mixer running on low speed, add buttermilk in a slow, steady stream and mix until incorporated. Add remaining half of the dry ingredients and mix to combine.

Pour half of the batter into the prepared cake pan, and spread into an even layer. Sprinkle about half of the crumble mixture over the batter in an even layer.

Pour remaining batter on top, and spread into an even layer. Top batter with remaining crumble, scattering it fairly evenly across the surface.

Transfer cake to the preheated oven and bake until a tester inserted into the center comes out clean or with a few moist crumbs, 35 to 40 minutes.

Cool the cake completely in the pan, then use the excess parchment paper to gently unmold the cake and transfer to a cutting board. Slice the cake into 9 pieces, then peel it away from the parchment paper to serve.