Preheat the oven to 375ºF and position the oven rack in the upper third of the oven — not all the way at the top, but higher than the center. Baking the muffins in the upper area helps them rise better and brown evenly on top. Line a standard 12-cup muffin tin with paper liners and spray the liners with non-stick spray.
Whisk the oat flour, coconut sugar, cornstarch, baking powder, baking soda, salt, and cinnamon in a large mixing bowl. Set aside.
In a separate bowl, whisk together the eggs, milk, yogurt, olive oil, and vanilla extract until smooth.
Pour the wet mixture into the dry mixture and stir with a large spoon or spatula until everything is well incorporated. Fold in your mix-in (I use chocolate chips).
Distribute the batter evenly among the 12 muffin cups (a cookie scoop works well for this). Sprinkle with turbinado sugar (sugar in the raw) if desired. Bake for 14-16 minutes or until a toothpick inserted into the center of a muffin comes out clean (or with a few moist crumbs).
Allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.
If you enjoyed these, please leave a star rating in the recipe card — it helps others and makes my day! Thank you!