Place popcorn in a large bowl. In a microwave bowl, combine corn syrup and butter. Cover and cook on high for 30-45 seconds; stir. Pour over popcorn; stir to coat. Immediately add colored sprinkles, sugar and cinnamon; toss to coat. Transfer to two greased 15x10 inch baking pans; let stand for 1 hour or until dry. Store in airtight containers.