Preheat oven to 350°. Spray muffin pans with cooking spray.
Stir together oats, brown sugar, and ½ teaspoons cinnamon; set aside.
Beat butter and granulated sugar at medium speed with an electric mixer until fluffy. Add egg substitute, beating until blended. Stir in vanilla. Combine all-purpose flour, baking soda, baking powder, salt, and remaining ½ teaspoons cinnamon; add to butter mixture alternately with buttermilk, ending with flour mixture. Gently stir in blueberries. Spoon batter into muffin pans, filling two-thirds full. Sprinkle evenly with oat mixture.
Bake 15 to 20 minutes or until tops or golden. Cool muffins in pans for 5 minutes; remove from pans, and cool on wire racks.