In a medium bowl, combine all dry cupcake ingredients except for the carrots and raisins (in other words -- cake mix, flour, Splenda, brown sugar, pumpkin pie spice, cinnamon, and baking powder). Mix well and set aside.
In a large bowl, mix together pumpkin, egg substitute, and 1/4 cup water until blended.
Add the contents of the medium bowl to the large bowl. Using a wire whisk or fork, blend until just mixed. Then, stir in the carrots, pineapple, and raisins. Spray a 12-cup muffin pan with nonstick spray.
Evenly distribute cake mixture among the cups, and place in the oven to cook for 20 - 25 minutes (until a toothpick poked into the center of one comes out clean).
While the cupcakes cook, combine all the frosting ingredients in a small bowl. Using a whisk or fork, blend until smooth. Place frosting in the fridge to chill.
Once cupcakes are fully cooked, remove the pan from the oven and allow to cool completely. Then plate cupcakes, and spread frosting evenly over tops.
Refrigerate until frosting has set and you're ready to serve.