Preheat oven to 375 and grease an 9x9 baking pan with nonstick cooking spray and set aside. 

In a small bowl, combine 2 cups flour, baking powder and salt and mix well. Set aside. 

In a larger mixing bowl, cream butter and sugar together with a mixer. Beat until fluffy, about 3-5 minutes, scraping the sides of the bowl down halfway through. Add egg and vanilla and beat well. 

Add flour and milk, alternating between mixing and just until combined. 

Add 2 tablespoons flour with blueberries and toss well. Fold into batter. Pour into prepared pan and set aside while you combine the topping. 

Add flour, sugar and cinnamon to a bowl and mix well. Use a pastry blender, or two forks, to cut butter into mixture until small peas form. Sprinkle on top of batter. 

Bake for 45-55 minuts or until a toothpick inserted in the center comes out clean. Let stand to cool almost completely. Cut into 9 squares and serve warm.