• Preheat your oven to 350°F. Grease a standard 12-cup muffin tin and set it aside.

Drain the zucchini.

• Place the grated zucchini in the center of a large clean tea towel (a kitchen towel with a flat weave) or in a fine mesh bag.
• Gather the towel or bag around the zucchini, and twist tightly to squeeze out as much liquid as possible. It should reduce in weight by nearly half.
• Set the zucchini aside.

Make the muffin batter.

• In a large bowl, place the all purpose flour, xanthan gum, oat flour, baking soda, baking powder, salt, and sugar, and whisk to combine well.
• Add the grated zucchini and mix to combine, breaking up any clumps.
• Create a well in the center of the dry ingredients and add the coconut oil, eggs, and buttermilk, and mix to combine. The batter will be thick but not stiff.
• Add the chocolate chips, raisins or chopped nuts, and mix until they are evenly distributed throughout the batter.
• Fill the prepared wells of the muffin tins about completely full of batter. With wet fingers, smooth the tops of the batter in the wells.

Bake the muffins.

• Place the muffin tin in the center of the preheated oven. Bake for about 20 minutes, or until the tops of the muffins spring back when pressed gently and a toothpick inserted in the center comes out mostly clean, or with a few moist crumbs attached.
• Remove from the oven and allow to cool for at least 5 minutes before transferring to a wire rack to cool completely.
• If you have any leftover batter, repeat with whatever remains.

How to store leftover muffins.

• These muffins freeze very well in a freezer-safe container. Just eliminate as much air as possible from the container before freezing the muffins in a single layer.
• defrost on the counter overnight before serving. They can be refreshed in the toaster oven before serving.