Stout Brownies

Name: Stout Brownies
Prep time: 10 min
Cook time: 45 min
Total time: 45 min
Yield: 16 pieces
Ingredients: 225 g stout beer; 1 tsp instant espresso powder; 225 g sugar; 225 g unsalted butter; 285 g dark chocolate chip; 140 g all-purpose flour; 1 tbsp cornstarch; 3 tbsp cocoa powder (all types); &frac18; tsp baking soda; 1 tsp vanilla extract, natural; ¼ tsp salt; 3 large eggs; 1 egg yolk