Preheat the oven to 350°F (175°C) and line a 12-cup muffin tin with paper liners or spray with non-stick coating.
In a large bowl, whisk together the oat flour, protein powder, baking powder, baking soda, and salt until evenly distributed.
In a separate medium bowl, combine the Greek yogurt, eggs, honey, vanilla extract, and almond milk, whisking until the mixture is smooth.
Gradually incorporate the wet ingredients into the dry ingredients, stirring with a spatula until just combined to avoid overworking the batter.
Divide the batter evenly among the 12 muffin cups, filling each approximately three-quarters full.
Bake for 18 to 22 minutes, or until a toothpick inserted into the center of a muffin emerges clean.
Remove the tin from the oven and allow the muffins to cool in the pan for 5 minutes before transferring them to a wire rack for complete cooling.