Follow these simple steps to create your own Pumpkin Cinnamon Roll Muffins:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Line a muffin tin with paper liners or grease with cooking spray.
2. Mix Dry Ingredients: In a large bowl, whisk together the flour, baking powder, cinnamon, nutmeg, and salt.
3. Combine Wet Ingredients: In another bowl, mix the pumpkin puree, granulated sugar, brown sugar, vegetable oil, eggs, and vanilla extract until well combined.
4. Combine Mixtures: Gradually add the wet ingredients to the dry ingredients. Stir until just combined; be careful not to overmix.
5. Prepare Cinnamon Sugar: In a small bowl, combine the cinnamon sugar mixture (if using nuts, add them here).
6. Fill Muffin Tin: Spoon a small amount of batter into each muffin cup, just enough to cover the bottom.
7. Add Cinnamon Sugar: Sprinkle a layer of cinnamon sugar over the batter in each cup.
8. Top with Remaining Batter: Add more batter on top of the cinnamon sugar layer, filling each muffin cup about ¾ full.
9. Create Swirls: Use a toothpick or knife to gently swirl the batter and cinnamon sugar together for a marbled effect.
10. Bake: Place the muffin tin in the preheated oven and bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
11. Cool: Once baked, remove the muffins from the oven and allow them to cool in the tin for about 10 minutes before transferring them to a wire rack.

These steps will guide you in creating these mouthwatering muffins effortlessly!