In large mixing bowl cream together the butter and sugar; add the eggs and vanilla. Add the dry ingredients and mix thoroughly; the dough will be fairly stiff. Finally add the chocolate chips. On a greased cookie sheet, place 1 tbs of dough for each cookie, pressing down gently to flatten a bit. Bake in a 350 degree oven for about 12 minutes. When done, they will be slightly brown around the edges but still fairly white. Allow to cool before removing the cookies from baking sheet.