Line two baking sheets with parchment and set aside.
Combine butter, brown sugar, granulated sugar, and milk in a medium saucepan.
Warm over medium heat, stirring until melted. Bring to a steady boil and cook 1 minute.
Remove from heat. Stir in peanut butter and butterscotch chips until completely smooth.
Mix in vanilla, cinnamon, and salt.
Fold in oats until evenly coated and thick.
Scoop heaping tablespoons onto the lined sheets and gently flatten.
Let set at room temperature 20–30 minutes, or chill 15 minutes, until firm.
Notes
Variation ideas: Stir in 1/2 cup toasted pecans or shredded coconut, or drizzle set cookies with melted dark chocolate. For a salty-sweet finish, sprinkle flaky salt on top right after scooping.Storage: Keep cookies in an airtight container at room temperature up to 5 days, or freeze up to 2 months.This recipe is an original creation inspired by classic No-Bake Oatmeal Scotchies flavors. All ingredient ratios and instructions are independently developed.