PREP: Preheat the oven to 350 degrees F. Generously spray 8 of the muffin tin cavities with nonstick cooking spray. Do not use muffin liners! The muffins will stick to the sides.
DRY INGREDIENTS: In a large bowl, stir together the cocoa powder, oat flour (See Note 1), baking soda, baking powder, salt, and brown sugar.
WET INGREDIENTS: In a separate bowl, combine the peanut butter (do not warm up), applesauce, Greek yogurt, vanilla, honey and egg, Mix until completely combined.
FINISH BATTER: Add dry ingredients on top of wet and chocolate chips on top of that. Stir until just combined. Transfer the batter into the prepared muffin tin. If desired, top each muffin with a few more chocolate chips.
BAKE: Bake for 18-22 minutes or until a toothpick inserted in the center comes out clean. Remove and let cool in the muffin tin for 2-4 minutes and then gently coax out onto a cooling rack to finish cooling.