Begin the recipe by preheating the oven to 350 degrees F. and line a muffin pan with liners or lightly spray with cooking spray.
Using a food processor, pulse together the ⅓ cup granulated sugar, 8 teaspoons all-purpose flour, and 4 teaspoons brown sugar until combined.
Remove two tablespoons of this mixture and place into a small bowl and set aside. To the two tablespoons that you removed, whisk in 4 teaspoons brown sugar and 1 teaspoon ground cinnamon until combined.
To the mixture left in the food processor, add ⅓ cup all-purpose flour, ⅛ teaspoon baking powder, ⅛ teaspoon baking soda, ⅛ teaspoon salt, and pulse until combined.
Add the 4 tablespoons butter and pulse until the mixture resembles a coarse meal. Add the 1 large egg, Greek yogurt, and continue to pulse until the mixture is combined, making sure to stop and scrape the sides of the food processor as necessary.
Pour a generous tablespoon of the muffin mixture into each of the muffin liners, top with a tablespoon of the cinnamon mixture, and top with the remaining muffin mixture divided evenly. If you have any of the cinnamon mixture left, then you can sprinkle it on top.
Place the muffins in the oven and bake for 15 to 20 minutes or until a cake tester comes out clean. Carefully remove from the oven and allow the muffins to cool for about 10 minutes on a wire rack prior to serving. Enjoy!