Place 1 pint pistachio ice cream on the counter and let sit at room temperature until softened enough to easily stir, 20 to 30 minutes. It should be a little firmer than soft serve. Meanwhile, coat the sides of a 9x5-inch loaf pan with cooking spray and line the bottom and sides with parchment paper, leaving a few inches overhang on all sides. Coat the parchment with cooking spray. (Alternatively, line the greased loaf pan with plastic wrap and grease the plastic wrap.) Coarsely chop ⅓ cup roasted, salted pistachios and place in a medium bowl.

Add the pistachio ice cream to the bowl and use a spoon or stiff spatula to fold the pistachios evenly throughout the ice cream. Transfer to the loaf pan and spread into an even layer. Cover the pan with plastic wrap and freeze for 30 minutes. Meanwhile, place 1 pint vanilla ice cream on the counter and let sit at room temperature until softened enough to easily stir, 20 to 30 minutes. Scoop out 1 tablespoon maraschino cherry juice from 1 (6-ounce) jar maraschino cherries and add to a medium bowl. Drain the maraschino cherries and add to the cherry juice.

Add the vanilla ice cream to the bowl and use a spoon or stiff spatula to fold the cherries and cherry juice evenly throughout the ice cream until uniformly pink. Transfer to the loaf pan and spread into an even layer. Cover the pan with plastic wrap and freeze for 30 minutes. Meanwhile, place 3 cups chocolate ice cream on the counter and let sit at room temperature until softened enough to easily stir, 20 to 30 minutes. Place ¼ cup mini dark chocolate chips in a medium bowl.

Add the chocolate ice cream to the bowl and use a spoon or stiff spatula to fold the chips evenly throughout the ice cream. Transfer to the loaf pan and spread into an even layer. Cover the pan with plastic wrap and freeze until very firm, at least 5 hours or up to overnight.

Uncover the spumoni. Run a clean kitchen towel under hot water and rub the towel along the sides of the loaf pan a few times to loosen it, rewarming the towel as needed if the spumoni won’t budge. Using the overhang, carefully lift the spumoni out of the loaf pan and remove the parchment or plastic wrap. Place chocolate-side down on a cutting board and crosswise about 1-inch thick. Serve immediately.