Preheat the oven to 350 degrees. Grease and flour the cups of a muffin pan or line with paper liners.
In the bowl of a mixer, cream together the margarine and sugar. Add the egg and mix until incorporated. In a separate bowl, sift together flour, baking powder, baking soda, cinnamon, and salt. Add these combined dry ingredients to the mixer bowl. Stir in the remaining ingredients, squeezing out and discarding as much water as possible from the grated zucchini before adding.
Portion the batter into the muffin pan, filling each cup no more than 3/4 full. Sprinkle 3-4 extra chocolate chips on top of each muffin, if desired.
Bake for 17-20 minutes, or until an inserted toothpick comes out clean. Cool on a wire rack.