In a large bowl, whisk together the flour, brown sugar and ground cinnamon for the streusel topping. Work in the cold butter cubes until a sand like texture develops. Place the bowl in the fridge until the muffins are ready for topping.
Scoop a heaping tablespoon of muffin batter into each of the lined muffin wells. Top with a heaping teaspoon of cinnamon filling. Followed by another tablespoon of muffin batter on top of the filling. Top each of the muffins with a heaping tablespoon of the cinnamon crumble. Gently press the crumble into the muffins.
Bake the muffins for 10 minutes at 400 F (204 C). Reduce the oven temperature to 350 for the remaining time, about an additional 5-10 minutes.Cool the muffins in the hot muffin pan for 10 minutes. Enjoy!