Scrape down the bowl, and mix everything together. It will be the texture of a thick(ish) cake batter. Spread the batter evenly over the lined baking sheet, and then bake for 8-10 minutes or until dry and matte on the surface.
To assemble the sandwiches, get the ice cream out to soften for 10-15 minutes. Place a very large piece of plastic wrap onto a surface, and then place one of the frozen cookie pieces onto the plastic.
Working quickly, spread the ice cream over the cookie, sprinkling it with fudge as you go. Top with the other piece of cookie and press down gently, before wrapping tightly in plastic and placing back in the freezer for at least 2 hours.
For the cookies:
To build the sandwiches: