Pour cereal into a large bowl.
In a separate bowl melt chocolate chips, chocolate spread, and butter uncovered in the microwave for 1 minute on high; stir and microwave longer as needed until mixture can be stirred smooth, about 30 seconds. Add vanilla.
Pour mixture over cereal and mix until evenly coated. Divide and pour into two gallon-sized resealable plastic bags and add powdered sugar. Seal bags and shake until well coated.
Spread on waxed paper to cool and drizzle with melted mint chips. Store in airtight container.