Preheat the oven to 350°F. Lightly grease an 8x8 inch baking dish with nonstick cooking spray or coat it in butter.

Use an electric hand mixer to cream the butter and granulated sugar together in a mixing bowl. Set the hand mixer to a medium speed and mix until the ingredients are well combined.

Add the eggs and continue mixing on medium speed until the eggs are fully incorporated into the creamed sugar.

Add the flour and baking powder to the mixing bowl. Reduce the speed of the hand mixer to low and mix until the flour and baking powder are fully incorporated into the batter.

Spread the batter into an 8x8 inch baking pan and set aside. In a small dish, whisk together the ground cinnamon and brown sugar. Sprinkle the brown sugar mixture over the top of the cake.

Bake your cake for 40 minutes, or until a toothpick can be cleanly removed from the cake.
Once your cake is out of the oven, whisk together the milk, powdered sugar, and vanilla.

Drizzle this glaze over the top of the cake, slice, serve, and enjoy!