Preheat oven to 400 degrees F. Grease muffin tins.
Combine oats and buttermilk in a small bowl.
Mix together flour, brown sugar, salt, baking soda, and baking powder in a large bowl.
Add egg and melted butter into oat mixture and mix well.
Pour oat mixture into dry ingredients all at once. Stir just until moistened.
Gently fold in blueberries.
Fill muffin tins 3/4 way full. Bake for 15-22 minutes.