Place the margarine, sugars and milk beverage in a saucepan and place over medium-low heat. Whisk and cook until the sugars are fully dissolved. Remove from the heat and whisk in the vanilla, followed by the flour and salt.
Let cool for about 10 minutes, then stir in the chocolate chips.
Chill the dough for 2 hours or longer in the refrigerator.
Line a 4x8-inch to 8x8-inch pan with parchment (see Notes below). Evenly spread half of the dough on the bottom of the pan (return the rest to the refrigerator). Place it in the freezer. Remove the frozen dessert from the freezer and place it on the counter to soften - this may take 15 to 30 minutes, depending on which kind you use and your room temperature.
Remove the cookie dough pan from the freezer and evenly spread on the frozen dessert. Return to the freezer and let chill 2 hours or longer.
Evenly spread the remaining cookie dough on top of the frozen dessert, cover and chill until frozen solid, about 2 hours or longer.
Using the parchment, remove the cookie dough / frozen dessert block from the pan and cut into bars. Individually wrap and freeze the bars until ready to consume.
Notes
What Pan? How Much Frozen Dessert? The size of pan you use, and thus the amount of frozen dessert will depend on how thick you like your cookie dough. For a thin layer of cookie dough on bottom and top, use an 8x8-inch dish or similar and use 2 pints of frozen dessert (this will yield 12 to 16 ice cream sandwiches). For thicker layers of cookie dough, use an 8x4-inch dish or similar (I used a 7x5-inch dish for the cookie dough ice cream sandwiches shown with 1 pint of frozen dessert and got about 8 ice cream sandwiches) and just 1 pint of frozen dessert. If your pan falls somewhere in the middle size-wise, you may need 1½ pints of frozen dessert.
Recipe by Go Dairy Free at https://www.godairyfree.org/recipes/chocolate-chip-cookie-dough-ice-cream-sandwiches