Preheat oven to 350
In a mixing bowl cream together the butter and sugar.
Add the cinnamon, salt, vanilla, and eggs, and mix well.
Add the baking powder and flour, a little at a time, and mix until incorporated.
Spread into a greased 9x13" pan.
In a small bowl whisk together sugar and cinnamon and sprinkle evenly over cookie dough.
Bake for 20 minutes or until a toothpick inserted in the center of the pan comes out with fudgy crumbs. Do not over bake.
Let cool before cutting. Store tightly covered.