Combine the ice cream ingredients in a large bowl. Once they're well-combined, transfer the mixture to your ice cream maker and mix according to the manufacturer’s directions. I use the ice cream attachment that goes with my Kitchen Aid mixer. After churning the ice cream, place it in the freezer to solidify it. (Note: You'll only need about 2/3 of this ice cream for the sandwiches. You can store the rest in the freezer in an air-tight container or snack on it as you're working.)
To make the chocolate sandwich base, preheat the oven to 350 degrees and grease 2 8x8 inch pans. Place a piece of parchment paper in each pan.
Combine the wet ingredients in a large bowl.
In a small bowl, whisk together the dry ingredients.
Add the dry ingredients to the wet ingredients and mix to combine well.
Transfer the mixture onto the parchment paper and spread it evenly.
Bake for 8-10 minutes, until the sandwich base is set and the edges are pulling away from the sides a bit.
Cool completely on a wire rack.
To assemble, soften the ice cream slightly so that you can spread it. Don’t let it get runny.
Place one of the sandwich bases (top side down) on a piece of plastic wrap and spread 2/3 of the ice cream evenly on it. You can save the rest of the ice cream in the freezer for another time.
Put the other sandwich base on top of the ice cream (top side up) and wrap the whole thing with plastic wrap.
Freeze for at least 2 hours to let it solidify. Remove from the freezer and cut it in half. Then, cut each section into 6 sandwiches for a total of 12 sandwiches. Enjoy immediately or wrap the sandwiches individually and return them to the freezer.
Ingredients for vanilla ice cream are adapted from the Ben & Jerry's cookbook.