Preheat oven to 350 deg. Melt butter in very large bowl. Mix butter with both sugars, peanut butter, vanilla and eggs. Stir until creamy and smooth.
Add the flour, oats, baking soda and salt. Mix the dough until thoroughly blended. Stir in the chocolate chips until evenly distributed throughout the dough.
Roll dough into 1-1/2 inch balls and place on ungreased baking sheet, about 2 inches apart. Bake 12-15 minutes (13 min. worked in my oven), until the edges are golden brown. Cool completely. Makes 10 dozen.