This summery treat was so much fun to make!
Yield: 12, 2-by-4-by-1-inch ice cream sandwiches (24 cookies)
2 2/3 cups (335 grams) all-purpose flour
2/3 cup plus 1/4 cup (75 grams) extra dark or Dutch-processed unsweetened cocoa powder
1 1/4 cups (2 1/2 sticks or 285 grams) unsalted butter, softened
1 cup (200 grams) granulated sugar
3/4 teaspoon table salt
2 large egg yolks
1 tablespoon vanilla extract
1/2 gallon (8 cups or approximately 1050 grams, weight will vary by brand/variety) ice cream, your choice of flavor (I used cookies and cream), softened
Preheat oven to 350°F degrees. Line two baking sheets with parchment paper.
Sift the flour and cocoa together and set aside.
In the bowl of a standing mixer with a paddle attachment, beat the butter, sugar, and salt together until light and fluffy. Add the yolks and vanilla and mix until combined, then scrape down sides and mix briefly again. Add the flour mixture a little at a time then mix until combined.
Transfer the dough to a lightly floured work surface and divide into two equal pieces. If the dough is too soft to handle, wrap and chill it until firm enough to roll out (I recommend 30 minutes only; any longer and it becomes crumbly to roll out). Roll each batch into a 1/4-inch thick rectangle, about 10 by 8 inches. Cut into a total of 24 20 2-by-4-inch rectangles. You may have enough extra to reroll the scraps and create 4 more 2-by-4-inch rectangles, in which case, you could make two additional sandwiches.
Use an offset spatula to transfer the rectangles to the prepared sheets; you’ll only need an inch space between them. Use the tip of a thermometer to poke the cookies with holes (~14 holes).
Bake the cookies for 16 to 18 minutes, or until they stay firm when tapped in the center. Transfer to a wire rack to cool completely. Repeat with remaining cookie dough, rerolling scraps as needed.
Meanwhile, line the bottom of a 9-by-13-inch pan with parchment paper, allowing it to overhang on two sides (it will act as a sling for the ice cream). Spread the softened ice cream into the pan, smooth the top and freeze until firm, about one hour or more.
Run a knife along the exposed sides of the pan to loosen the ice cream. Holding onto the parchment paper, lift ice cream out of the pan and onto the work surface. Using one of the cookies as a template, cut ice cream into 10 to 12 2-by-4-inch bars (cut the number of cookie pairs your batch yielded). Then, flip each piece of ice cream onto a cookie, peel off the paper, and finished sandwiching the rectangle of ice cream with a second cookie.
(If your ice cream begins to soften, just slide it back into the freezer for a bit and it will become easy to work with again.)
Wrap each ice cream sandwich in plastic.
Freeze until just before serving.