Preheat oven to 375° Fahrenheit and line a muffin tin with muffin liners.
In a large bowl, mix together the Greek yogurt, milk, olive oil, maple syrup, eggs, and vanilla extract.
Add in the oat flour, rolled oats, baking powder, and baking soda and mix until fully combined and the batter is smooth.
Fold in any fruit or chocolate chips you're using until it’s evenly distributed throughout the batter.
Then, scoop ¼ cup of batter into each muffin liner and bake muffins for 20-25 minutes, or until a toothpick inserted down the center of a muffin comes out clean. Remove the muffins from the oven and let them cool before serving or storing.