Grease a 9" round springform pan with cooking spray on the bottom and sides. Set aside. Meanwhile, add the butter and miniature marshmallows to a large microwaveable bowl and microwave on HIGH power for about 30 seconds. Stir, then continue microwaving in 30 seconds intervals, stirring after each interval, until melted and smooth. Add in the Fruity Pebbles and stir quickly to combine. Pour the coated cereal mixture into the prepared pan and press into a crust using a greased bottom of a glass. Let set for about 20 minutes.

For the cheesecake: In the bowl of a stand mixer, cream together the cream cheese, sugar, and vanilla with the paddle attachment until fluffy and smooth, about 1 minute. Add in the marshmallow creme and beat well to combine. Lastly, fold in the whipped topping, making sure to scrape the bottom and sides of the bowl to get everything mixed cohesively.

Spread the cheesecake into the crust and smooth out the top. Cover and refrigerate for at least 4-6 hours, preferably overnight, before serving. Just before serving, garnish the top with cherry pie filling.