In large mixing bowl, combine the flour, sugar, baking powder, salt, milk and egg. Stir together. Add the butter and beat vigorously for 30 seconds.
Grease a round 9 inch baking pan with butter. Add a Tablespoon of flour into the pan and "flour" the pan. Dump out the excess flour. If you don't have a 9 inch baking pan, you can use on 8 or 9 inch square pan.
Spread the batter into your greased and floured pan.
In a small bowl, combine your topping ingredients. With a pastry cutter, or fork, mix until crumbly. Sprinkle topping over batter. Bake 25-30 minutes or until wooden toothpick comes out clean when inserted into center of cake.
Recipe by Vixen's Kitchen at https://www.vixenskitchen.com/coffee-cake/