Preheat the oven to 350 degrees F and make sure the oven rack is in the center position.

Line a 12-cup muffin tin with paper cups, and place 4 paper cups inside a second muffin tin. Add 2 tablespoons of water to each of the remaining empty muffin wells.

Combine all the cupcake ingredients in a bowl, adding the water last. Beat with an electric mixer until smooth. Divide the batter evenly between the lined muffin cups. Bake until risen and golden in color and a toothpick inserted into the center of 1 cupcake comes out clean, 20 to 25 minutes.

To make the icing, combine all the ingredients in a large mixing bowl. Blend with a hand-held mixer until smooth and creamy.

Remove from the oven and carefully transfer to a wire rack to cool completely. Using a small spatula or butter knife, spread either Vanilla or Chocolate icing onto each cupcake (using about 2 tablespoons per cupcake). If desired, place optional toppings on separate plates and dip the cupcakes into desired toppings and serve.