Place the ingredients for the ice cream into a mixing bowl, and beat on high until soft to stiff peaks form. This will happen more quickly than usual thanks to the addition of the xanthan gum, so keep an eye on it so that it does not over whip.
Layer the mixture evenly in a loaf pan, and freeze for 5-6 hours before serving.
Add the ingredients for the cookie bars to a mixing bowl, and beat on high until a dough has formed.
Press the dough into an even layer on a parchment lined 9x13 baking sheet.
Score the bars into 12 even sections with a sharp knife, and use the tines of a fork to poke holes all over the top of the dough.
Bake for 10-15 minutes until cooked through, and let cool completely. If there is some excess butter on the top of the bars when you remove them from the oven, simply dab it away gently with a paper towel.
Once the cookie bars are cooled, sandwich a serving of the ice cream between two of them to create an ice cream sandwich.
Repeat step 11 with the remaining cookie bars, and serve.