Preheat oven to 350°F and line a 13 x 9 pan with parchment paper or nonstick foil.
In a large saucepan, heat ½ cup stout and butter over low heat until butter is melted.
Remove from heat and add cocoa powder and stir till cocoa powder is dissolved. Add remainder of stout beer and stir.
Mix in eggs and yolks.
Stir in sugar.
Add in flour and salt till combined.
Pour batter into lined pan and bake about 30 minutes until the top of the brownies form a crust and the edges look baked.
Cool completely, cut into squares (or footballs!) and enjoy!
Notes
Letting these brownies cool overnight will give them the most ideal texture.If you're making these for a tailgate or Super Bowl party, cut into footballs instead of squares. See the tips and tricks section above for how to do this.