Here's a step-by-step guide on how to bake brownies in disposable aluminum pans: **Ingredients:** * 1 and 1/2 sticks of unsalted butter (12 tablespoons), plus more for greasing the pan* 2 cups of sugar* 4 large eggs* 1/2 cup of unsweetened cocoa powder* 1 teaspoon of vanilla extract* 1 and 1/4 cups of all-purpose flour* 1 teaspoon of salt* 1 cup of semi-sweet chocolate chips* Optional: nuts,...