Crush half of the biscotti into tiny crumbs. Spread them evenly along the bottom of a 12” by 9” baking dish. Do not pack down crumbs.
In a mixing bowl, combine the softened cream cheese and marshmallow fluff. Mix well.
Fold in the whipped topping one cup at a time. Mix well with a spatula. Do not use a hand mixer or stand mixer.
Using a clean spatula, gently smooth the cheesecake mixture over the biscotti crumbs. Work from the outside in and make sure to move large amounts. The crumbs are not stuck to the bottom of the pan, so work gently not to mix in the crumbs.
Top the cheesecake layer with the cherry spread. Carefully spread all over the top.
Chill for at least 1 hour before serving.
Break up the remaining biscotti for dipping. Serve.