Preheat the oven to 350º Fahrenheit. Grease an 8x8 baking pan with cooking spray.
In a medium bowl, whisk together the flour, baking powder, salt and sugar.
Use a pastry cutter or two knives to cut in the cold butter until the mixture is crumbly.
Add the egg and milk. Mix well.
In a small bowl, mix together the flour, sugar and cinnamon. Cut in the butter until the mixture resembles coarse crumbs.
Spread the batter in the greased baking pan.
Sprinkle the cinnamon topping over the cake batter.
Bake for 25-30 minutes or until the cake tests done.
The calories shown are based on the cake being cut into 9 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**