1.In a small bowl, combine ½ tsp cinnamon and the brown sugar together. Generously spray a 9-inch Bundt pan with cooking spray and sprinkle the sugar mixture to evenly coat the inside of the pan. Set aside
2.In a medium bowl, mix the peaches with 2 teaspoon cinnamon and ½ teaspoon nutmeg until coated. Set aside. In a large bowl, whisk together flour, baking powder, salt, and 1 teaspoon cinnamon and 1/2 teaspoon nutmeg until combined. Set aside.
3.In a bowl of a stand mixer with whisk attachment add egg whites and beat until they reach medium peaks (about 3 minutes) then transfer to another bowl. Set aside. In the same bowl with a paddle attachment cream together the butter with sugar at medium speed until light and fluffy (3-4 minutes).
4.Add in the egg yolks one at a time, mixing well after each addition. Add in the peach schnapps and vanilla and mix well. Slowly add the flour mixture into the wet ingredients and mix until just combined.
5.Preheat your oven to 325 degrees. Using a spatula, add buttermilk then half of the egg whites and gently fold the egg whites into the batter. Pour half of the batter into the prepared pan and top with sliced peaches. Pour the remaining batter over top of the peaches and use a spatula to smooth them out.
6.Bake in preheated oven for about 90 minutes, or until a toothpick inserted in the center comes out clean. Remove the pan from the oven and allow it to sit for 10-minutes. Once 10-minutes has passed, place your cooling rack over top of the pan and carefully flip onto the rack. Gently lift the pan and allow the cake to cool. Serve after 15 minutes.