Line a 11×14-inch baking pan with parchment paper and lightly grease with cooking spray. Set aside. Set 12 Circus animal cookies to the side and chop up the rest to get about 4 cups worth. Melt butter in a large pot and stir in the salt.
Measure out and set aside 1½ cups of marshmallows to mix in at the end. Add the remaining marshmallows to the pot to melt with the butter and stir until it is a smooth consistency. Take the pot off of the heat before adding in the vanilla and food coloring. Stir until you get a nice pink color. Add another drop at a time of food coloring if needed.
Fold in the Rice Krispies cereal, 4 cups chopped Circus Animal Cookies, white chocolate chips, and sprinkles. Add the 1½ cups of reserved mini marshmallows and fold gently into the mixture. Spread the mixture into the baking pan into an even layer. It helps to use a greased rubber spatula or grease your hands to press it in.
These circus cookie Krispie treats are best enjoyed the day they’re made! Though if you do have leftovers, you can store them at room temperature in an airtight container for up to 2 days.