In a large mixing bowl, combine flour, sugar, baking powder, cinnamon and salt.
Gently fold in blueberries. In a small bowl, whisk together the egg, milk and butter. Add to the flour mixture and stir carefully.
Spread into a greased 8-in. x 8-in. baking pan. Combine all topping ingredients and sprinkle over batter.
Bake at 425 F 218 C for 20-25 minutes or until top is light golden brown.
Serve warm or at room temperature.