Chocolate-Bar Easter Cake
["8 oz. milk chocolate bar, broken into chunks", "1/4 c. butter", "1 2/3 c. boiling water", "2 1/3 c. unsifted all-purpose flour", "2 c. packed light brown sugar", "2 tsp. baking soda", "1 tsp. salt", "2 eggs", "1/2 c. sour cream", "1 tsp. vanilla", "chocolate frosting"]
["Preheat oven to 350\u00b0.", "Combine chocolate, butter and water in a mixing bowl.", "Stir until chocolate is melted.", "In a separate bowl combine flour, brown sugar, baking soda and salt.", "Gradually add chocolate mixture, beating for several minutes with electric mixer on medium speed until well blended.", "Add eggs, sour cream and vanilla, continuing to beat on medium speed for 1 minute. Pour into greased and floured 9 x 13-inch pan.", "Bake for 35 to 40 minutes.", "Cool.", "Top with your favorite chocolate frosting."]
["milk chocolate", "butter", "boiling water", "flour", "brown sugar", "baking soda", "salt", "eggs", "sour cream", "vanilla", "chocolate frosting"]