Preheat the oven to 350 degrees Fahrenheit and line a muffin tin with paper liners or silicone liners.

Transfer the oats to a high-powered blender and blend until a flour forms, about 60 seconds.

Add the remaining dry ingredients (sugar, protein powder, baking powder, cinnamon and salt) to the blender and blend to combine all of the dry ingredients.

In a large mixing bowl, mix together the eggs, Greek yogurt, egg whites, avocado oil, and pure vanilla extract.

Pour the dry ingredients into the bowl with the wet ingredients and mix until a smooth batter forms.

Place blueberries in a separate large bowl and toss them with 2 teaspoons of gluten-free all-purpose flour or regular all-purpose flour. If you don’t have flour on hand, skip this step.

Transfer the blueberries and lemon zest to the muffin batter and mix well.

Fill the muffin cups all the way up with muffin batter. If you’d like, place extra blueberries on top of the batter.

Bake on the center rack of the preheated oven for 18 to 22 minutes, or until the muffins test clean and are baked through.

To test for doneness, insert a digital thermometer into the center of a muffin and wait until the numbers stop moving. If the muffins are 190 degrees on the inside or hotter, they are fully baked. The ideal internal temperature for muffins is between 190 and 205 degrees F.

Allow muffins to cool to room temperature before removing them from the muffin pan. Once the muffins have cooled completely, you can peel off one of the papers and enjoy! I don’t recommend peeling off the liner while the muffin is still warm because you will lose some of the muffin to the liner.

Store muffins in an airtight container or ziplock bag in the refrigerator for 3-5 days. You can also freeze muffins in a large freezer bag for up to 3 months.