Preheat the oven to 350°F (177°C) and line a muffin pan with 11 liners. I use parchment paper liners or the Reynolds Staybrite and they never stick.
To a large bowl, add the oat flour, potato starch, cocoa powder, baking soda and salt and whisk very well. I then sifted everything over a mesh strainer to ensure everything was smooth, as my cocoa powder was very lumpy. If yours is, I highly recommend the same so you turn out smooth muffins. Set aside.
Peel and slice some zucchini and THEN weigh 150 grams. I used about 1 1/2 small zucchini. It's important to weigh the zucchini AFTER you've peeled and sliced it, so you get the exact right amount of moisture.
Add the sliced zucchini and the 1/2 cup + 2 tablespoons (150g) water to a food processor or blender and blend until completely smooth. See photo for reference. This will be your zucchini puree.
Add the zucchini puree, syrup, vanilla and chocolate chips to the bowl of dry ingredients.
Stir gently around the bowl and the bottom until smooth and mixed, being careful to mix just until combined, as oat-based batters can turn into dense muffins if over-mixed.
Divide the batter into 11 muffin liners. Using an ice cream scoop helps to make the perfect size and nice rounded dome tops when they bake up. Place a few extra chocolate chips on top, if desired. Sure makes them look prettier.
Bake for 18-20 minutes. Mine were perfect at 18 minutes for each trial. They should be super fluffy and firm to the touch. A toothpick should basically be clean, but it's hard to check if they are done that way with all the chocolate chips in there, which can be deceptive, so poke around a few times with a couple of different toothpicks to check for doneness.
Cool 15 minutes in the pan. This is rather important to let them cool before eating, as they will still be finishing cooking and if you try to eat one right out of the oven, they will taste under-baked and gummy. Cooling will result in a tender, fluffy muffin. Now devour and enjoy that amazing rich chocolate decadence!
POTATO STARCH: I highly recommend purchasing the potato starch if you can. It provided fluffy results in a way no other starches do. This works great in gluten-free baked goods that have a lot of moisture, like these with zucchini and water, so that they don't turn out gummy. It can be a bit hard to find in stores, so I just order it online from Amazon. It is very affordable and arrives quickly. Additionally, I use it for a lot of recipes here on my blog, so it is a great investment if you are a gluten-free baker.