Preheat oven to 350.
Spray muffin pans with cooking spray.
Stir together oats, brown sugar, and 1/2 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 1/2 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.