Preheat Oven & Prep Your Pan. Preheat the oven to 425 degrees F. Line a muffin pan with parchment muffin liners or grease to prevent sticking.
Combine Dry Ingredients. In a large bowl, combine gluten free flour, baking powder, baking soda, salt, and cinnamon. Whisk to combine.
Combine Wet Ingredients. In a medium bowl or large liquid measuring cup, combine orange zest, orange juice, milk, avocado oil, honey, eggs, and vanilla. Whisk till smooth.
Add Wet Ingredients To Try Ingredients. Add wet ingredients to the dry ingredients and stir until mixture is just combined and there are no large powdery spots left (some small lumps are fine).
Fold In Cranberries. Add cranberries to the batter and gently fold in, to combine. (If desired, reserve a few cranberries for the top of your muffins to make them extra pretty).
If Possible: Let The Batter Rest 30-60 minutes. This will give your muffins a taller rise!
Scoop the Batter into 12 muffin cups (muffin cups will be full). Add any reserved cranberries to the tops of the muffins and gently press into the batter, if desired. Sprinkle the tops of the muffins with sugar.
Bake at 425 degrees F for 5 minutes, then reduce oven temperature to 350 degrees and bake an additional 12-15 minutes, or until the muffins are golden brown and a toothpick inserted in the center of the muffin comes out clean with just a few moist crumbs. Remove muffins from the oven and let cool 1-2 minutes in the muffin pan before transferring to a wire rack to finish cooling.
Serve & Store. Enjoy right away or store in an airtight container at room temperature 1-2 days, in the fridge for 3-4 days, or in the freezer up to 2 months.