Preheat the oven to 350°F and line a muffin tin with parchment liners or lightly grease it.
In a large bowl, whisk together the dry ingredients — the flours, baking powder, baking soda, pumpkin pie spice, salt, and collagen (if using).
In a separate bowl, mix the wet ingredients — pumpkin purée, eggs, maple syrup, melted coconut oil, and vanilla — until smooth and combined.
Combine the wet and dry ingredients, stirring gently until just mixed.
Fold in the chocolate chips or any other add-ins you love.
Scoop the batter evenly into 12 muffin cups (they’ll be fairly full).
Bake for 22–26 minutes, or until a toothpick inserted in the center comes out mostly clean.
Let cool in the pan for 5 minutes, then transfer to a wire rack to finish cooling.