Preheat the oven to 350°F (175°C) and line a 12-cup muffin tin with parchment liners.

In a large bowl, whisk together the oat flour, protein powder, baking powder, baking soda, and salt until no clumps remain.

In a separate medium bowl, whisk the Greek yogurt, eggs, maple syrup, almond milk, lemon juice, lemon zest, and vanilla extract until well emulsified.

Create a well in the dry ingredients and pour in the wet mixture, stirring with a spatula until just incorporated.

Gently fold the fresh blueberries into the batter, taking care not to overwork the dough or crush the berries.

Divide the batter evenly among the 12 muffin cups, filling each approximately three-quarters full.

Bake in the center rack for 18 to 22 minutes, or until a toothpick inserted into the center of a muffin comes out clean.

Remove from the oven and allow muffins to rest in the pan for 5 minutes before transferring to a wire cooling rack.