Preheat the oven to 350 degrees F and line a muffin tray with muffin papers (or spray with cooking spray).
Add all ingredients except grated zucchini and chocolate to a blender. Blend until completely smooth. Fold in the grated zucchini and chocolate chunks/chips.
Spoon the batter into the prepared muffin tray, filling the holes 3/4 of the way up with batter.
Bake on the center rack of the oven 30 to 40 minutes, or until muffin tops are golden-brown and muffins have baked through.
Allow muffins to sit at least one hour before removing the papers to consume (note: if you try peeling off the papers too early, they will stick to the muffins).