5. FREEZE the ice cream in the ice cream machine, per the manufacturer’s instructions. Scoop into a freezer safe container, and place in the freezer to firm up while you prepare the brownies. (The ice cream can be made up to a week in advance. If you’ve made it ahead of time, let it rest on the counter for about 5 minutes to soften before assembling the ice cream sandwiches.)
6. BAKE the brownies. Preheat oven to 350°F. Lightly grease an 11″ × 17″ jelly roll pan with cooking spray, and line with parchment paper.
7. STIR together the chocolate and butter in a small saucepan set over medium heat, until melted and smooth, about 3-4 minutes. Remove from heat.
8. COMBINE the chocolate mixture in a large mixing bowl with the sugar, vanilla extract and salt; and stir until smooth. Add the eggs one at a time, beating well after each addition, then add the flour and stir until just barely combined. Pour the batter into the prepared pan, and smooth out the top to create a very thin, evenly distributed layer.
9. BAKE in the preheated oven for about 8-10 minutes, or until the brownies are set and shiny on top, but still slightly undercooked. Remove from oven and set the pan on a wire rack to cool completely, about 30 minutes.
10. CUT the brownie layer in half lengthwise to create two long, skinny rectangles, and place in the freezer for 10-15 minutes to firm up.
11. ASSEMBLE the sandwiches: Run a knife along the edge of the pan to loosen the brownies. Carefully lift one of the rectangles out and transfer to a wire rack, leaving the other half on the cookie sheet.
12. USING the parchment, carefully flip over the brownie layer in the pan, so that it’s now top-side down. Remove the parchment paper.
13. WORKING as quickly as possible, spread the ice cream in a smooth, even layer onto the brownie in the pan. Carefully place the remaining brownie on top of the ice cream, doing your best to align the two layers. Wrap tightly with plastic wrap, and transfer to the freezer for at least 2-3 hours, or until completely frozen. When ready to serve…
14. USE a sharp knife to cut into 8 rectangular pieces, then slice each one diagonally to create 16 triangular sandwiches. Serve right away. Wrap any sandwiches you’re not eating immediately in plastic wrap, and store in the freezer until ready to serve or up to 1 month.
Find more delicious peanut butter recipes at ILovePeanutButter.com.