For the Rice Krispies:

• Line a 9×13 pan with parchment paper. Lightly mist with nonstick cooking spray and set aside. In a large pot melt your butter. Once melted, stir in the two teaspoons of vanilla extract. The hot mixture will bubble up, so continue to stir an additional thirty seconds until the sizzling subsides.
• Add in one bag or half of your marshmallows and mix until almost completely melted before adding the remaining. Stir until all of the marshmallows are entirely combined and melted. You may need to return to low heat to melt.
• At this point, add in the Rice Krispies, 2 cups at a time, and lightly stir until combined. Continue to add the Rice Krispies and then the Fruit Loops until everything is evenly combined. Pour the mixture into the 9×13 pan. Lightly wet your hands and gently push into the pan to the edges. You don't want to crush it, so really be gentle with it!
• Add the white chocolate to a heat proof bowl. Microwave for 30 seconds, stir and repeat until completely melted. Once it's ready, set aside for 3 minutes to come down to room temperature. Pour onto the treats and spread evenly on top. Sprinkle on rainbow sprinkles and extra Fruit Loops and enjoy!