1. Preheat oven to 450F. Spray a 10-inch cast iron skillet, or 10-inch round cake pan with nonstick spray.

2. In a medium size bowl, make the cinnamon sugar crumble. Add the flour, cinnamon and sugar to the bowl and stir to combine. Add in the butter and use a fork to claw the ingredients together. Store in refrigerator until ready to use.

3. In a large bowl, add sifted flour, baking powder, baking soda and salt. Alternatively, you can add all of these ingredients to the bowl and use a whisk to combine. The whisk acts as a way to sift flour, incorporating air and breaking up clumps.

4. Add butter and use a pastry knife or fork to cut the butter into the flour mixture until small pea sized morsels remain.

5. Add in the buttermilk and apples and stir until combined. 

6. Scoop the dough into large roughly 6 tablespoon, or heaping 1/3 cup amounts into the prepared pan. You should have 8 biscuits.

7. Sprinkle the crumble topping over the biscuits.

8. Bake in preheated oven 15-20 minutes, or until a toothpick inserted into the center of the biscuits comes out clean.

9. Make the icing. In a small bowl, stir together the powdered sugar and heavy cream or whole milk. Drizzle over the biscuits. Serve and enjoy!