Heat oven to 350°F. Grease and flour the inside of a 2-1/2- to 3-quart ovenproof glass bowl, such as Pyrex. In a medium bowl, combine quick-bread mix with water, eggs, and oil. Stir for 1 minute, or until well blended. Pour into prepared glass bowl.
Place glass bowl on a baking sheet and bake for 55 to 60 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool 10 minutes. Invert cake onto wire rack and let cool completely.
Draw the shape of a heart onto the inverted cake using food-coloring marker. Cut to shape into a heart, using a sharp knife. Tint frosting red using icing color; frost cake. Using your fingers, shape fondant into arms with hands and legs with sneaker-covered feet. Roll a piece of fondant out to flatten and make eyes, mouth, and nose for face; attach to cake. Place 2 red M&M's into fondant circles for eyes.