Begin by lining a 5-inch glass bowl with plastic wrap, ensuring there is a 3-inch overhang for easy removal later. Spoon softened chocolate ice cream into the bowl, spreading it evenly to form the base layer. Next, place the Amarena cherries on top of the chocolate ice cream, gently pressing them down. Drizzle the hot fudge over the cherries, followed by half of the crushed amaretti cookies, evenly distributing them along the sides of the bowl.

Layer the softened vanilla ice cream on top, smoothing it into an even layer. Press the remaining crushed amaretti cookies into the vanilla layer to establish a solid cookie base. Fold the plastic wrap over the top of the tartufo and place the bowl in the freezer overnight to allow the layers to set.

The following day, melt the dark chocolate chips and coconut oil together in a small microwave-safe bowl. Heat in 30-second intervals, stirring between each session until fully melted; then set aside.

Once the tartufo has frozen, remove the bowl from the freezer. Carefully take out the molded ice cream by peeling away the plastic wrap. Place a small piece of parchment paper over the cookie base, then flip the molded ice cream onto a wire rack set over a baking sheet. Gently release the ice cream from the plastic wrap.

Pour the melted chocolate sauce over the tartufo, ensuring it is thoroughly covered. Finish by sprinkling with chopped hazelnuts for an added crunch. Serve immediately or return to the freezer until ready to enjoy.