In a large bowl combine the cereal, pretzels, marshmallows, M&M's. Mix them up a bit to evenly distribute.

Meanwhile, over a double boiler or in the microwave, melt the white chocolate according to package instructions.

Once the chocolate is melted and smooth, drizzle it over the cereal mix, pretzels, marshmallows, and M&Ms. Combine with a spoon, spatula, or your hands. Be sure the cereal mixture is evenly coated with chocolate. Melt a little more if needed.

Spread the mixture onto a large sheet of parchment or wax paper. Let dry and harden for a few minutes. While it hardens, scatter some seasonal sprinkles for extra flair. Break it into bite-size pieces, combine with the larger Reese's Pink Heart (if using), and store it in airtight containers or baggies for up to 1 week.