Beat butter and brown sugar in large bowl of an electric mixer, until creamy; beat in eggs and vanilla.
In separate bowl, stir together flour, baking soda, and salt; gradually add to butter mixture, blending thoroughly.
Add oats, chocolate chips, and nuts; mix well.
Shape each cookie by spooning dough into a 1/2-cup measure, level off, and turn out onto a greased baking sheet. Space cookies a minimum of 6 inches apart and 2 1/2 from edge of baking sheet.
Lightly grease the bottom of a pie pan, dip in granulated sugar, and use to flatten each cookie into a 5 1/2-inch circle. To even each cookie's thickness, press it lightly with your finger, if necessary.
Bake in a 350 degree farenheit oven for about 15 minutes or until edges are lightly browned. Place on baking sheets and allow to cool for 5 minutes; transfer to racks to cool completely.