Instructions

Preheat oven to 350°F. Butter the sides and bottom of a 9×13-inch glass baking pan. Line the pan with parchment paper.

In a medium bowl, whisk the flour, salt, and cocoa powder together. Place the chocolate and butter in a saucepan (or using a double broiler) over medium-low heat, stirring occasionally, until the chocolate and butter are completely melted and smooth. Turn off the heat, but keep the and add the sugar and brown sugar. Whisk until completely combined, then remove pan from stovetop and allow to come to room temperature.

Add 2 eggs to the chocolate mixture and whisk until combined. Add the root beer extract and stir until combined. Do not overbeat the batter at this stage or your brownies will be cakey.

Sprinkle the flour mixture over the chocolate mixture. Using a rubber spatula (not a whisk), fold the flour mixture into the chocolate until just a bit of the flour mixture is still visible.

Pour the batter into the prepared pan and smooth the top. Bake in the center of the oven for 30 minutes, rotating the pan halfway through the baking time, until a toothpick inserted into the center of the brownies comes out with a few moist crumbs sticking to it.

Let the brownies cool completely, then lift them out of the pan using the parchment paper.

While they’re cooling, prepare the frosting: in a stand mixer fitted with a paddle attachment, beat the butter until creamy. Slowly add in powdered sugar and salt, and beat until light and fluffy. Take out half of the frosting, and set aside in a bowl. Mix in vanilla powder to one half of the frosting (by hand is fine) and root beer extract to the other half.

Frost cool brownies by swirling the frostings together and spreading over the top. I thought I would do this very elegantly and make a cool pattern, but I did not. I think it would be possible to if you have more skill than me!

Cut into squares and serve. Store at room temperature in an airtight container or wrap with plastic wrap for up to 3 days.