Preheat the oven to 350°F Grease one 9x13-inch pan or two 9-inch round cake pans.
Combine flour, salt and baking powder and set aside. Cream together butter and sugar until light and fluffy. Add eggs one at a time, beating well after each. Add milk and vanilla and beat untill combined. Add the flour mixture and beat until smooth.
Pour into pans and bake 25-30 minutes or until toothpick inserted comes out clean.
Cool for 15 minutes in pan. Remove and cool completely on wire rack before frosting. Makes one 9x13-inch or two 9-inch cakes.