Crumb Topping

1. Combine the sugars, flour, cinnamon, salt, and butter for the topping in a small bowl with a fork until it starts to clump. You can use your hands to break up any bigger pieces.
2. Chill until ready to use.

Cinnamon Crumb Muffins

1. Preheat oven to 400º F.
2. In a large bowl, whisk together the flour, baking powder, salt, and cinnamon and set aside.
3. In a stand mixer fitted with a paddle attachment or with a handheld mixer mix the sugars and butter together on medium speed until light and fluffy.
4. Add the eggs, one at a time, with the mixer on medium speed, and scrape down the sides of the bowl as needed.
5. Add the sour cream and mix just until combined. Scrape down the sides of the bowl.
6. Add the flour mixture and mix just until combined.
7. Scoop the batter into 12 muffin liners, so that each liner is about ¾ full. Sprinkle the crumb topping evenly on top of each muffin so that all of the batter is covered.
8. Bake muffins for 5 minutes. Turn oven down to 350º F and continue to bake for another 14-15 minutes until golden brown. Let muffins cool slightly on a cooling rack. Enjoy!