Cream together the butter, sugar and light brown sugar.
Add the eggs and vanilla, stir.
Add the flour, peanut butter, baking soda and salt, stir.
Add the chocolate chips, stir.
Place balls of dough on a baking sheet and bake at 350° for 10 minutes.
Tip: press the dough balls down slightly before putting them into the oven. Otherwise cookies may not flatten.