Spray a large microwave-safe mug with nonstick spray. Add cocoa mix, cake mix, egg substitute, and 2 tablespoons water. Mix well.
Add chocolate chips and about a third of the pudding to the mug, and stir gently to combine. Microwave for 1 minute.
Fluff with a fork, and then gently mix in the remaining pudding. Microwave for 1 more minute.
Let cool slightly. Top with whipped topping and garnish with mint, if using. Dig in!
PER SERVING (entire recipe): 223 calories, 5g fat, 588mg sodium, 45.5g carbs, 2.75g fiber, 19g sugars, 6.5g protein