In a large bowl of a stand mixer fitted with a paddle attachment, beat butter, peanut butter, brown sugar, and granulated sugar for 2-3 minutes until creamy and light.
1 cup salted butter, 2/3 cup creamy peanut butter, 1 1/2 cups brown sugar, 1 cup granulated sugar
Add eggs, egg yolks, vanilla extract, baking soda, and salt. Beat again until incorporated and smooth.
2 large eggs, 1 Tablespoon vanilla extract, 1 teaspoon baking soda, 1 teaspoon salt
Add oats, mixing on low speed just until barely mixed together. Add flour and mix again just until combined. Do not overmix.
2 cups old-fashioned oats, 3 cups all-purpose flour
Add chips, mixing just until they are evenly spread throughout the cookie dough. Refrigerate for 2 hours.
1 cup chocolate chips, 1 cup butterscotch chips, 1 cup peanut butter chips
Preheat oven to 400°F. Line two baking sheets with parchment paper. Use a large cookie scoop to measure out 3.7-ounce balls of cookie dough. Shape into large pucks and space them out six to a pan on the baking sheets.
Bake for 10-11 minutes. Let cool for 10 minutes before transferring to a wire rack.