In a large saucepan, melt together the melted butter with the miniature marshmallows. Cook, while stirring over medium heat until the marshmallows are melted. Stir in the Rice Krispies.
Butter a 9″ pie dish, or spray with non-stick cooking spray. Scoop in the rice krispie mixture, and press down with your hands along the bottom & up the sides of the pie dish forming your pie crust. If you hands stick, grease your hands with a little butter or cooking spray. Once you have the pie crust formed, set aside.
In a large bowl. dump out the contents of a 3oz berry blue Jello container. Pour in ½ cup of boiling water & whisk til dissolved. Stir in ½ cup of cold water. Refrigerate until partially set, about 45 minutes.
In a medium sized bowl, beat 2 cups of heavy whipping cream until it begins to thicken. Sprinkle in ⅔ of a cup of confectioners sugar. Continue beating until soft peaks form. You can omit this step & use Cool Whip if you like. Remove one dollop of the fresh whipped cream & set aside. Nothing large, just about 3-4 tablespoons. Gently fold in the blueberries (making sure you have just a few blueberries left over for garnish – 6-8 blueberries will do).
Now, fold in the partially set berry blue jello until combined.
Scoop the mixture into the prepared rice krispie treat crust & spread evenly to fill. Place the dollop of fresh whipped cream you reserved earlier on the very center of the pie & garnish with the few blueberries you saved.
Refrigerate for 2 hours before serving to allow the pie time to set. Store in the fridge.