In a large bowl beat together the butter, sugars, and peanut butter until fluffy.Mix in the egg and vanilla. With the mixer on low speed, carefully beat in the flour, baking soda and salt. Then mix in the oats.Preheat the oven to 350F degrees. Form the dough into balls about 1 - 1.5 tablespoons in size.Place 2 inches apart on a lined cookie sheet. Do not flatten. Then bake for 8-10 minutes or until the tops are just set.
