Peanut Butter Oatmeal Cookie Granola Bars (no-bake, vegan, gluten-free)

unsalted butter (half of one stick) or vegan butter

milk (regular, soy, or nut milk)

granulated sugar

light brown sugar, packed

heaping cup creamy peanut butter

vanilla extract

old-fashioned whole rolled oats (not quick cook or instant, use certified gluten-free if necessary)

crispy rice cereal (Rice Krispies or similar, use certified gluten-free if necessary)

butterscotch/peanut butter/semi-sweet chocolate chips melted for drizzling, optional (use peanut butter or semi-sweet chocolate to keep vegan)

unsalted butter or vegan butter for drizzling