Preheat your oven to 350°F (175°C). Prepare your fudgy brownie mix according to package instructions and pour the batter into a greased 9x9-inch baking pan. Bake for 20–25 minutes until a toothpick inserted in the center comes out with a few moist crumbs. Once baked, remove from the oven and allow the brownies to cool completely in the pan on a wire rack.

While the brownies cool, take your chosen ice cream out of the freezer and allow it to soften at room temperature for about 10 minutes. This will make spreading the ice cream easier over the cooled brownie layer.

Once the brownies are completely cooled, evenly spread the softened ice cream over them using a spatula. Ensure the surface is smooth for an even layer.

Next, sprinkle your brownie chunks generously over the ice cream layer. Gently press them down into the ice cream to secure them in place.

Place the pan in the freezer, allowing the cake to freeze for at least 4 hours until it is completely firm. Once set, drizzle warm chocolate sauce across the top, optionally adding whipped cream before serving.