This is that cookie recipe that everyone needs in their life. My Aunt Linda gave this to me when I was in grade school, and I've been making variations of it ever since. I remember making it for friends in grade/middle school, for high school fundraisers, for catered events when I was a hospitality student at Washington State University, and they have graced many a picnic buffet ever since.
I love these because you can really throw in whatever you want as "embellishments." This is the version I usually end up with, but clean out your candy/nut/baking drawer, and go to town. And be prepared to share the recipe (or just send askers to my cookbook, A Perfect 10, where my official recipe exists). Good luck!
Mix the base - 2/3 cup softened butter, 1 1/4 cup brown sugar, 3/4 cups sugar, 3 lightly beaten eggs, and 2 teaspoons of baking powder. Once mixed well, add 1 1/2 cup chunky peanut butter, and combine well. Then stir in about 5 or 6 cups of old-fashioned oats.
At this point, add whatever snacks you want. I typically add 1/2 cup each of milk chocolate chips and butterscotch chips...but I've been known to add some variations of coconut, walnuts, M&M's, raisins, toffee chips...go to town.
Cook on greased cookies sheets at 350 for 11 minutes. I like them soft - just as they start to barely brown, take them out.
Ooey gooey yumminess!