Preheat the oven to 350 F. Line two 12-cup standard muffin tins with paper cupcake liners and set aside.
In a bowl, using an electric mixer, mix the cake mix, 1 1/3 cups water, oil and eggs on medium speed until moistened and smooth. Stir in 3/4 cup chocolate chips. Divide the batter evenly among the muffin cups, stirring it occasionally to redistribute the chocolate chips. The batter will nearly fill each liner to the top. Evenly sprinkle the remaining 1/4 cup chocolate chips over the tops of the cupcakes. Bake until the cupcakes spring back when lightly touched, or a toothpick inserted in the center comes out clean, about 20 minutes. Transfer to a rack to cool.
When cool, put the White Faux Buttercream out with spoons or small spatulas along with bowls of the cupcake toppings for the kids to decorate their own cupcakes.
In the bowl of a stand mixer, using the paddle attachment, whip the butter on high speed until very soft. Meanwhile, place a large sheet of parchment paper on a work surface. Using a large sifter, sift the confectioners' sugar onto the parchment. This helps prevent clumping and makes the mixing easier. Lower the speed of the mixer and, using the parchment as a funnel, pour half the sugar into the bowl and mix slowly until combined. Add the milk and mix until combined. Once combined, add the remaining sugar with the vanilla and mix. Once it is combined, turn the mixer speed up and beat the icing until very light and fluffy, 3 to 4 minutes. If desired, divide the icing into smaller batches and color with food coloring.
Spread the icing on cooled cupcakes while at room temperature. Refrigerate any leftover icing, but be sure to let it come back to room temperature before using. Re-whip the icing to make it fluffy again. Makes 4 cups (enough for 24 cupcakes).
Yield: about 8 cups, enough for at least 6 dozen cupcakes