Chewy Turtle Cake
["3 Tbsp. boiling water", "2 oz. sweet chocolate", "3/4 c. sugar", "1/4 plus 2 Tbsp. butter, softened", "2 egg yolks", "1/2 tsp. vanilla", "1 c. cake flour", "1/2 tsp. soda", "2 egg whites", "caramel topping"]
["Pour boiling water over chocolate and stir until melted. Cool. Beat sugar and margarine until fluffy.", "Beat in egg yolks. Beat in chocolate mixture and vanilla on low speed."]
["boiling water", "sweet chocolate", "sugar", "butter", "egg yolks", "vanilla", "cake flour", "soda", "egg whites", "caramel topping"]