Line a 9 x 9 square pan with parchment paper and spray with nonstick spray.Set aside.
In a large stove top pan, combine coconut oil and marshmallows over medium heat. Heat until the mixture is almost completely melted. Stir constantly as the bottom can burn quickly.
Add in 4-5 cups of rice krispie cereal, depending on how gooey you like your treats. Add in candy corns and sprinkles. Mix well.
Place mixture in pan. Lightly press more candy corns and sprinkles into the top.