Prep: Preheat the oven to 375 degree F. Spray a 9 x 13 baking pan with non-stick cooking spray and set aside.
Batter: In a medium size bowl, melt the butter in the microwave and then add in the milk and sugar, stir to combine.
In a separate small bowl, crack your two eggs and beat together with a fork. Then pour it to the butter and sugar mixture.
Add in the flour, baking powder and salt. Stir well to combine.
Pour into the greased cake pan and set aside.
Make Topping: Mix together the brown sugar, cinnamon, flour and the melted butter, stir to combine.
Then, sprinkle on top of uncooked cake to cover the whole cake.
Bake: Put in the preheated oven and bake for 35-40 minutes. Let cool for 5-10 minutes.
Glaze: Whisk powdered sugar and hot water until smooth, then drizzle it over slightly cooled cake. Slice, serve warm and enjoy!