Mix egg, banana, carrot, sugar, and Greek yogurt in a mixing bowl till well blended.
Fold in pumpkin pie spice and self rising flour.
Grease 4 silicon muffin cups. Fill equally with batter.
Bake at 350 for 15-20 minutes, or until a knife comes out clean.
While it's baking, mix the cream cheese and zero calorie powdered sugar together. Add to a piping bag, and pipe your frosting on top of cooled muffins.