Preheat the oven to 350 degrees Fahrenheit. Pop the microwave popcorn according to package instructions and allow it to cool slightly. Combine sugar and cinnamon in a small bowl.
Place the first 5 ingredients into a large mixing bowl. Drizzle with melted butter and sprinkle the cinnamon-sugar mixture over all. Stir gently to coat the snacks. Spread the mixture on two large baking sheets in a single layer. Bake for 12 to 14 minutes.
Remove the mixture from the oven and add the chocolate rice cakes. Melt the white chocolate according to package instructions and drizzle over the warm snack mix. Refrigerate the trays until chocolate has set, 25-30 minutes.
Place snack mix in airtight tins for gifting or in sealable plastic bags until ready to serve. Recipe makes 12 cups of snack mix or 12 servings.
Equipment
1 large mixing bowl
2 large sheet pans
Notes
Additions/Substitutions for Snickerdoodle Snack Mix: