Preheat oven to 350 degrees
Prepare your 9x13 inch pan
In a medium mixing bowl, add the flour, salt and baking soda and baking powder. Whisk together and set aside.
In a stand mixer, cream the butter and sugars together
Add the egg and vanilla
Slowly add the flour mixture
Beat together until it makes a dough
Bake for 15-20 minutes. Make sure to not overcook