1/4 (120 g) semisweet or bittersweet chocolate chips or wafers
1/2 cup (50 g) walnuts or pecans, toasted and chopped
1 quart high quality chocolate chip ice cream
Beat the butter with the granulated and brown sugar in the bowl of an electric stand mixer or a hand held mixer, until smooth. Beat in the egg and vanilla.
In a separate bowl, whisk together the flour, baking soda, and salt, making sure there are no lumps of baking soda. Stir the dry ingredients into the creamed butter mixture, then mix in the chocolate chips and nuts. Wrap the dough in plastic wrap, flatten it into a disk, and chill for at least 1 hour.
Preheat the oven to 350 degrees F (175 degrees C). Line 2 baking sheets with parchment paper or silicone baking mats.
Form the dough into sixteen 1-1/2-inch (4-cm) rounds. Flatten the rounds of dough into 3-inch (8-cm) disks spaced evenly apart on the baking sheet. Since they don’t spread much, you can leave 1 inch (3 cm) of space between them.
Bake the cookies for 15 minutes, rotating the baking sheets midway during baking, then remove from the oven.
Once cool, sandwich ice cream between 2 cookies, then wrap each ice cream sandwich in plastic wrap and store in the freezer.