CopyKat.com is the creation of Stephanie Manley. Stephanie started publishing recipes on the web in 1995 as a means to capture her family recipes in a format that they would not be thrown away.
Over the years 
The first time we heard of this, we wondered how good a shake with Rice Krispies could be. Well we were really surprised because this shake is really good. Jack in the Box is known for tasty and inventive fast food. They have a large variety of menu items, such as egg rolls, tacos, burgers, mini burgers, and much more. They are known for their creativity, and this shake definately fits the bill.
Jack in the Box uses premium ice cream, so we suggest that you use a good quality of ice cream. We really liked Blue Bell Old Fashioned Vanilla Ice Cream, and our second choice was Blue Bunny Vanilla Ice Cream.
Jack in the Box Marshmallow Rice Krispie Shake
1 C. vanilla ice cream
2 Tbsp. milk
1 Tbsp. Marshmallow Fluff
2 Tbsp. Rice Krispies
First combine the ice cream, milk, marshmallow fluff, together, when you get this to the consistency you desire, stir in the Rice Krispies, and gently stir them in.
Now if you don’t want to buy the Marshmallow Fluff, and the cereal, Rice Krispies makes a Rice Krispie Treat cereal. Make the same way as listed before but without the Marshmallow fluff. These are good too, but we like using the fluff and the cereal.
While I have never been to Jack in the Box, I made this shake today. It was really good! I altered mine slightly: use 2-3 tablespoons of fluff instead of 1 and mix the milk and fluff before introducing the ice cream. Otherwise the fluff will freeze in a giant glob.
Surprisingly good. The texture of the rice krispies really goes well with vanilla ice cream. I’ve tried the marshmallow fluff and it just doesn’t seem to work for me. When I try to use the fluff, it just gets hard from the cold and sticks in a clump instead of mixing. If you want to use the fluff, try mixing it in a blender. However it is much easier to use the rice krispie treats cereal instead of the regular cereal.