For the Basic Brownies
8 tablespoons (4 ounces) unsalted butter
6 ounces bittersweet chocolate, finely chopped
2 ounces unsweetened chocolate, finely chopped
1 cup (7 ounces) plus 2 tablespoons granulated sugar
3 large eggs
1/2 teaspoon salt
2 teaspoons vanilla extract
1 cup (5 ounces) all purpose flour
2 tablespoons cocoa

Boozy Fruit and Nut variation:
2 teaspoons bourbon
3/4 cup dried cranberries, divided
3/4 cup raisins, divided
1 cup chopped almonds, divided

Salty Peanut Blast variation:
1 1/4 cup peanuts, chopped, divided
5 tablespoons natural peanut butter
1/2 teaspoon coarse salt

Hazelnut and Nutella Swirl variation:
1 cup hazelnuts, chopped
6 tablespoons Nutella