Melt 4 tablespoons of unsalted butter in a medium saucepan over low heat. Stir gently to prevent burning.

Add 5 cups of mini marshmallows and stir until completely melted and smooth, about 3–5 minutes.

Remove from heat and fold in 6 cups of puffed rice cereal, ensuring every piece is well-coated. Press down evenly in the pan.

Mix in 1.5 cups of white chocolate chips until evenly distributed. Optionally reserve half a cup for drizzling later.

Allow to cool for about 10 minutes. Lightly grease hands and roll small portions into 1-inch balls.

Drizzle melted white chocolate over the balls and sprinkle with festive sprinkles while still warm. Let them set at room temperature for 15–20 minutes.

Store leftovers in an airtight container at room temperature for up to 3 days.