In a large bowl or stand mixer, beat together the butter and brown sugar. Add eggs and vanilla and mix until smooth. Add the flour, baking soda, and salt and mix until just combined. Stir in the oats and the rest of the mix-ins.
Heat oven to 350°F before you scoop the cookies so that it’s fully heated when you’re ready to put them in.
Form the cookie dough into heaping tablespoon balls about 2 inches apart on a parchment-lined baking sheet. Flatten the cookie dough balls with the back of a spatula.
Bake cookies for 9-11 minutes, taking them out when barely golden at the edges. Let cookies cool on the baking sheet for a few minutes before transferring them to a cooling rack.