First, pulse together the ice cream and cinnamon in a blender. Create a sling with parchment paper in a 9x13 baking dish. Spread the ice cream mixture out evenly and place into the freezer.
In the bowl of a stand mixer, combine butter and brown sugar until fluffy. Add the egg and molasses. In a separate bowl, combine the dry ingredients. Gradually incorporate the dry into the wet until mixed well. Cover and chill for 1-2 hours.
Preheat oven to 350°. On a lightly floured surface, roll the dough out to about 1/4 (4mm) inch thickness Using a holiday cut-out of your choice, cut through dough and place onto a baking sheet lined with parchment paper. Bake 8-10 minutes. Remove and cool completely.
Take ice cream out of the freezer. Using the same holiday cut out, cut through the ice cream making the same shape as the cookies. Sandwich the ice cream between two cookies. Wrap each in plastic or wax paper. Have all your supplies set out and ready-ice cream melts quickly! Place back into the freezer until ready to eat.