Instructions

1. Preheat oven to 350°F. In a microwave-safe bowl, melt the butter. Remove from microwave, stir in sugar, and melt both for 30 seconds. Stir again and melt for 60 seconds more. You want the sugar and butter to bubble up slightly, but not burn. This amount of time should do the trick.
2. Remove mixture from microwave and stir in bittersweet chocolate. This should melt the chocolate completely. If it doesn’t, put it in the microwave for another 15 seconds. Whisk in the eggs, one at time. Whisk until glossy and bubbles form on top.
3. Add the rest of the ingredients and mix until just combined.
4. Pour batter into a parchment lined 8″x8″ pan. 
5. Bake for 30 minutes, or until a knife inserted in the center of the brownies comes out clean. Allow to cool completely before frosting.
6. While the brownies cool, make  the frosting. Beat all ingredients in a stand mixer fit with the paddle attachment on low speed, gradually increasing to high. Beat for 1 minute or until light and fluffy.
7. Frosted the cooled brownies and sprinkle with mini marshmallows. Use a large knife to cut into 9 big brownies! Enjoy!