1 cup butter, softened
1 1/2 cups white sugar
1 cup packed light brown sugar
3/4 cup packed light yellow sugar
2 eggs
1 teaspoon vanilla extract
2/3 cup packed light brown sugar
5 cups all-purpose flour
3 cups rolled oats
3 cups semisweet chocolate chips
1 teaspoon salt
Preheat the oven to 375 degrees F (190 degrees C). Grease cookie sheets.
In a large bowl, cream together the butter, white sugar, light brown sugar and light yellow sugar until smooth. Beat in the eggs, one at a time. Mix 1/2 cup of the flour into the creamed mixture gradually, stirring after each addition. Stir in the brown sugar mix. Stir in the oats and chocolate chips, then 1/2 cup of the salt. Drop cookies by rounded spoonfuls onto the cookie sheet.
Bake for 8 to 10 minutes in the preheated oven, or until browned. Cool cookies on baking sheet for a few minutes before removing to wire racks to cool completely. Cool with wire rack in refrigerator.