Preheat the oven to 350 degrees F. Line a 12-cup muffin pan with foil baking cups and/or spray with nonstick spray.
For the cupcakes:
In a tall glass, combine cocoa mix with 2 ounces hot water. Stir until cocoa dissolves. Add 6 ounces cold water and stir well.
In a large mixing bowl, combine cake mix, egg substitute, sweetener, and salt. Add cocoa mixture and whisk until smooth.
Evenly distribute cake mixture among the prepared muffin cups.
Bake in the oven for about 15 minutes, until a toothpick inserted into the center of a cupcake comes out clean. Remove from oven and let cool.
To make the glaze:
Put the marshmallow creme in a small dish. Add soymilk and mix well.
Once the cupcakes have cooled completely, drizzle marshmallow glaze over them. Top each cupcake with 1/4 teaspoon chocolate chips and one mini marshmallow.
Refrigerate until ready to serve. Garnish the cupcakes with additional chocolate chips and marshmallows, if using.