Mocha Walnut Brownies
["16 oz. dark brown sugar", "3/4 c. unsalted butter", "2 Tbsp. vanilla", "2 c. flour", "2 tsp. baking powder", "1 c. chopped walnuts", "1 c. semi-sweet chocolate pieces", "2 Tbsp. strong instant coffee", "1 Tbsp. hot water", "2 eggs", "1/2 tsp. salt", "frosting (optional)"]
["Heat the brown sugar and butter in a medium-size saucepan over medium-low heat until the butter has melted.", "Dissolve the coffee in the hot water and stir into the butter mixture.", "Let cool to room temperature.", "Preheat oven to 350\u00b0.", "Butter an 8 x 11-inch baking pan.", "When the butter mixture is cool, beat in the eggs and vanilla.", "Sift the flour, baking powder and salt together.", "Stir into the butter mixture with a wooden spoon.", "Stir in the walnuts and chocolate.", "Spread evenly in the pan with a rubber spatula. Bake 25 to 30 minutes until light brown.", "Cool and cut into bars. Frost and sprinkle with nuts, if desired.", "Makes 20 brownies."]
["brown sugar", "unsalted butter", "vanilla", "flour", "baking powder", "walnuts", "semi-sweet chocolate pieces", "coffee", "water", "eggs", "salt", "frosting"]