Preheat oven to 350 degrees. Prepare 2 (12 count) muffin tins with cupcake liners, or spray with non-stick cooking spray.
In a large bowl, mix together all of the ingredients for the cake, and whisk until batter is smooth. Divide the batter evenly between the 24 muffin tins. Bake in preheated oven for 20-25 minutes, or until toothpick comes out clean.
Meanwhile, in a small bowl, whisk together the milk and pudding mix until smooth. Fold in cool whip, rum extract, and pumpkin pie spice. Chill frosting in the fridge until the cupcakes are completely cooled, and ready to be frosted.
When cupcakes are ready to frost, place whipped frosting in a large ziplock bag. Cut the tip off a corner of the bag, and squeeze frosting down to the cut corner. Squeeze frosting out while making a swirling/upward motion and lift at the peak! Dust with cinnamon if desired. Store cupcakes in fridge until ready to serve.