Butterbeer 2 liter cream soda 2 tablespoons Butter extract 2 teaspoons rum extract *drop the extracts into the 2 liter bottle, put on cap and slowly rotate until combined. Cream topping 1 7oz container of marshmallow creme 1 cup whipping cream 1 teaspoon rum extract *add all items together in an electric mixer and combine until smooth. Pour the butterbeer into a glass, drizzle with the cream topping, and enjoy! Here’s what we liked about this one: The downside: