Preheat your oven: Set it to 350°F and line a 12-cup muffin tin with paper liners or grease well.
Mix the wet ingredients: In a large bowl, whisk together the pumpkin puree, eggs, oil, granulated sugar, brown sugar, and vanilla until smooth.
Add the dry ingredients: Stir in the flour, baking soda, baking powder, salt, and pumpkin pie spice until just combined. Don’t overmix.
Create the chocolate swirl: Scoop out about 1/3 of the batter into a separate bowl. Stir in the cocoa powder until well blended.
Layer the batters: Spoon a bit of the plain pumpkin batter into each muffin cup, then add a spoonful of the chocolate batter. Top with more pumpkin batter until cups are ¾ full.
Swirl it: Use a toothpick or knife to gently swirl the batters together in each muffin cup.
Add chocolate chips: Sprinkle extra chocolate chips on top of each muffin.
Bake: Bake for 18–20 minutes or until a toothpick inserted into the center comes out clean.
Cool: Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.