Preheat the oven to 400 degrees F. Cut the pumpkin in half and roast for 20 to 25 minutes. When cool enough to handle, scoop out the pumpkin and puree in a food processor with the cinnamon, ginger, nutmeg, rum and vanilla. Mix the spiced pumpkin puree into the ice cream base and freeze as per your home ice cream machine instructions.
After the ice cream has reached its partially frozen state, layer it with the Ginger Molasses Cookie Dough in 18 small or 12 large ramekins (for individual servings) or a 13-by-9-inch pan (for multiple servings). Fill your container halfway, crumble the cookie dough balls over the top and then fill the container to the top with the rest of the ice cream. Freeze for 45 minutes to an hour prior to serving.
Cream the softened butter and sugar. Add the molasses, cream and oil and blend well. Mix in the flour, salt, ginger and cinnamon. Refrigerate until firm enough to form into balls. Form into 1-inch balls.
This is an eggless dough intended to be eaten "raw" and is not suitable for baking.