Preheat the oven to 400F.
Mash the Banana: Add egg and brown sugar. Mix until fully combined. Add greek yogurt and grated and squeezed zucchini. Mix to combine.
Sift the cocoa powder, all-purpose flour, baking powder, baking soda and salt.
Add the almond flour and manually mix until no more raw ingredients showing.
Add chocolate chips and mix until distributed.
Scoop in a large muffin tin. Top with more chocolate chips.
Bake at preheated 400F for 10 minutes in the lower rack. Then lower the temperature to 350F and bake for another 5 minutes. Transfer in the middle rack and bake for another 12 minutes.*** Because this is large muffin, baking in the lower rack will help the bottom of the muffin bake well. Baking in the middle rack will help bake the top of the muffin.