Preheat the oven to 350 degrees Fahrenheit. Line a cookie sheet with parchment paper or non-stick baking mats.
In a large bowl, combine the butter, peanut butter, and sugars. Mix well.
1 stick unsalted butter, 1 ¼ cup creamy peanut butter, 1 cup granulated sugar, 3/4 cup packed light brown sugar
Add 1 egg at a time, scraping the dough from the edges of the bowl in between. Add the vanilla.
3 large eggs, 1 teaspoon vanilla extract
In a second large bowl, add the oats, flour, baking soda, and salt. Mix until combined.
2 teaspoons baking soda, 3 cups rolled oats, 1 ¼ cup all-purpose flour, 1/2 teaspoon salt
Add the dry ingredients to the bowlwith the wet ingredients, and mix until they are just combined.
Fold in the M&M’s, chocolate chips, and butterscotch.
1/2 cup chocolate chips, 1/2 cup M&M’s candy, ½ cup butterscotch chips
Portion the dough into 1/4th cup-sized balls, roll them, and place them 4 inches apart on the prepared cookie sheet. Gently press them down slightly, but careful not to flatten too much.
Bake for 8-10 minutes. Be careful not to overbake!
Let them stand for 3 minutes before transferring them to a wire rack to cool completely.
Store in large resealable plastic bags or an airtight container for up to 1 week.