Preheat oven to 350 f
Spray muffin tray or line with parchment liners.
Combine eggs, nut butter, maple syrup, pumpkin, baking soda, & vanilla; just until smooth.
Remove 2 cups batter, and place in a separate bowl.
In original bowl, add cacao powder & chocolate chips, mix well.
Scoop 1/2 of EACH batter into each muffin tin, so it's half chocolate, half pumpkin color.
Swirl batters together using a toothpick.
Bake in preheated oven for 25-30 minutes until toothpick comes out clean. They are VERY moist if they are NOT overbaked.