Prepare your shaping tools (rolling pin or inverted muffin tin) by spraying them heavily with non-stick cooking spray.

In a large pot over low heat, melt the butter. Add the marshmallows and stir constantly until completely smooth. Remove from heat immediately.

Add the Fruity Pebbles to the pot and fold gently until all the cereal is coated with the marshmallow mixture.

Spray your hands with cooking spray. Take about 1/2 cup of the warm mixture and press it into a 5-inch flat circle on parchment paper.

Immediately drape the warm cereal circle over your prepared rolling pin to form a taco shape. Let set for 30 minutes until hardened. Repeat with remaining mixture.

In a chilled bowl, beat the cold heavy cream until stiff peaks form. Set aside.

In a large bowl, beat the softened cream cheese, powdered sugar, vanilla, and lemon juice until completely smooth and fluffy.

Gently fold the whipped cream into the cream cheese mixture until just combined. Transfer to a piping bag.

Pipe the cheesecake filling generously into the hardened cereal taco shells.

Decorate with rainbow sprinkles and chill for 1 hour before serving.