I'm a big fan of shortcut desserts, which is why this showstopper is one of my favorites! Make it look even more impressive by piping the whipped cream on top using a large star-shaped piping tip.
Technique tip: Let it sit at room temperature for 5-10 minutes for easy slicing.
Line a 9- by 5-inch loaf pan with parchment paper, leaving an overhang of 3 inches on the long sides. Place all but 1/4 cup of the raspberries in a small bowl. Mash with a fork. Push the mashed raspberries through a fine-mesh strainer into a bowl, discarding the seeds. Stir 1/4 cup powdered sugar into the mashed raspberries.2.
In a large bowl, using an electric mixer, whip the cream, the remaining 1/2 cup powdered sugar, and the vanilla to medium-soft peaks. Reserve 2 tablespoons of the raspberry puree for serving; fold the remaining puree into the cream.3.
Place 3 or 4 ice-cream sandwiches in prepared loaf pan, cutting to fit. There will be some room on the ends of the pan. Spread one third of the cream mixture on top. Repeat layers two more times, using 4 ice-cream sandwiches crosswise on the final layer. If desired, transfer remaining cream to a large piping bag fitted with a star tip and pipe rosettes on final layer. Freeze until firm, at least 4 hours.4.
To serve, spoon over reserved raspberry puree, reserved raspberries and other fresh berries.