Preheat oven to 325 degrees F (165 degrees C) and place rack in center of oven. Butter, or spray with a non stick vegetable spray, an 8 inch (20 cm) square baking pan.
(personally, I like to line the pan with Parchment for easy of removal and spray the paper.)
Melt the chocolate and butter in a large stainless steel bowl placed over a saucepan of simmering water. Remove from heat and stir in the sugar. Next, whisk in the vanilla extract and eggs, one at a time, beating well after each addition. Finally, stir in the flour and salt.
Pour into the prepared pan and bake for about 25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Remove from oven and immediately sprinkle the brownies with the chocolate chips, miniature marshmallows and chopped nuts. Return the brownies to the oven and bake for about 5 minutes, or just until the marshmallows start to melt. Remove from oven and let cool on a wire rack. Makes 16 brownies.

Sources:
Lebovitz, David. The Great Book of Chocolate. Ten Speed Press. Berkeley: 2004.
http://www.dreyersinc.com/about/WebHistory.pdf
Rocky Road Brownies:
4 ounces (120 grams) unsweetened chocolate, coarsely chopped
1/2 cup (113 grams) unsalted butter, cut into pieces
1 cup (200 grams) granulated white sugar
1 teaspoon pure vanilla extract
2 large eggs
3/4 cup (95 grams) all-purpose flour
1/4 teaspoon salt
If you are in a hurry, start with a box of brownie mix! Bake as directed, then add the Rocky Road!
Make your brownies as you like them, fudgy or cake like – typically less egg the more fudgy you want.
Topping:
1/2 cup (85 grams) semi sweet or milk chocolate chips
1 cup (250 ml) miniature marshmallows (store bought or home made)
1/2 cup (50 grams) chopped nuts (walnuts, pecans, almonds, hazelnuts, peanuts, and/or pistachios)