In a medium to large saucepan, melt the butter over medium to medium-low heat. Add the sugar, milk, and cocoa powder and mix until combined. Stir in the peanut butter, Nutella, and Frangelico until melted, followed by the oats. Continue mixing until all of the ingredients are incorporated. Reduce heat to lowest setting.
Working quickly, use a spring-form ice cream scoop to shape balls of dough and place them on a parchment-lined sheet pan. Refrigerate for thirty minutes until firm. Store in an airtight container.