In brief
King Arthur Baking's peanut butter marshmallow pie uses a prebaked, cooled shell and a fluffy filling. The assembled dessert chills before serving.
Useful to know
King Arthur Baking's peanut butter marshmallow pie uses a prebaked, cooled shell and a fluffy filling. The assembled dessert chills before serving. [1]
A pie therefore does not necessarily mean baking every component together. Read the method in stages: shell preparation, separate filling, assembly and refrigeration.
Sources
For further detail and to check the information: