Preheat oven to 350 degrees. Lightly spray 24 mini muffin tins with nonstick cooking spray and set aside.
Melt butter and bittersweet chocolate over medium-low heat. Remove from heat and stir in sugar. Stir in vanilla and egg. Add in all dry ingredients and slowly mix to incorporate.
Spoon into prepared pan and bake for 8 minutes. Let cool 2 minutes, remove, and top with ice cream. Add sprinkles or any other toppings desired and serve immediately.