Start by baking your favorite chocolate cake in a 9x13 pan. You can use a box mix for convenience or make one from scratch. Once baked, allow the cake to cool completely. Once cooled, cut or crumble cake into small, bite-sized pieces. Set aside.
In a small bowl, combine 1/2 cup of hot water with 3 teaspoons of instant coffee or espresso powder. Stir until the coffee is fully dissolved and set aside to cool slightly.
In a large bowl of a stand mixer make the homemade whipped cream. Whip 2 cups of heavy whipping cream with 3 tablespoons of powdered sugar until stiff peaks form. Be careful not to overbeat and transfer to a separate large mixing bowl.
In the same bowl of a stand mixer, beat 8 oz of mascarpone cheese with 8 oz of thawed whipped topping until smooth and well combined. Add in the coffee mixture and mix well.
Gently fold the whipped cream into the mascarpone and whipped topping mixture until fully incorporated.
Begin by placing a layer of the chocolate cake pieces at the bottom of a glass trifle dish or any clear, large glass bowl.
Spread a layer of the creamy mascarpone coffee mixture over the cake, ensuring it covers the cake evenly.
Sprinkle a portion of the chopped Heath bars over the cream layer for that delightful toffee crunch. Repeat the layers two more times, finishing with a final sprinkling of Heath toffee bits pieces on top.
Refrigerate the trifle for at least 2 hours before serving. This chilling time allows the flavors to meld together beautifully.
Serve the trifle cold, and enjoy every luscious bite. This dessert stays fresh for up to 3 days in the refrigerator, making it a great make-ahead option