This step can be tricky as the ice cream starts melting during the process, making it tough to spread. Begin by opening your jar of hot fudge and warm it very slightly so it's easier to spread. It should not be hot. Then remove your pie from the freezer and quickly drop small spoonfuls all over the surface of the ice cream. With a knife or offset spatula, immediately smooth the topping, joining all the dollops of fudge together. Return to the freezer.