Ultimate Chocolate Brownies
["3/4 c. Hershey's cocoa", "1/2 tsp. baking soda", "2/3 c. butter, melted and divided", "1/2 c. boiling water", "2 c. sugar", "2 eggs", "1 1/3 c. flour", "1 tsp. vanilla extract", "1/4 tsp. salt", "1 c. Hershey's semi-sweet chocolate chips", "One-Bowl Buttercream Frosting"]
["Heat oven to 350\u00b0.", "Grease rectangular pan, 13 x 9 x 2-inches or two square pans, 8 x 8 x 2-inches.", "In medium bowl, combine cocoa and baking soda.", "Blend in 1/3 cup melted butter.", "Add boiling water.", "Stir until mixture thickens.", "Stir in sugar, eggs and remaining 1/3 cup melted butter.", "Stir until smooth.", "Add flour, vanilla and salt; blend completely.", "Stir in chocolate chips.", "Pour and bake 35 to 40 minutes.", "Allow to cool and frost."]
["cocoa", "baking soda", "butter", "boiling water", "sugar", "eggs", "flour", "vanilla extract", "salt", "chocolate chips", "Buttercream Frosting"]