Preheat oven to 350 degrees.
3 cups flour
1/4 teaspoon salt
1 cup sugar
4 teaspoons baking powder
1-1/2 cup milk
2 eggs
2 teaspoon vanilla
1/2 cup butter, melted
Mix everything for 2 minutes except for the butter. Slowly stir in butter and pour into a greased 9X13 pan.  

1 cup butter, softened
1 cup brown sugar
2 tablespoon flour
1 tablespoon cinnamon
Mix all the topping ingredients together until well combined. Drop evenly over the batter and swirl with a knife.

 Bake at 350 degrees for 28-32 minutes

2 cups powdered sugar
5 tablespoon milk
1 teaspoon vanilla
Drizzle glaze over cake while it is still warm.