I'm not exactly sure how this came to mind. I like translating desserts, and last year I made a delicious tiramisù ice-cream (which I will hopefully recreate for an upcoming blog), and I thought doing a dessert mashup for millionaire's shortbread would also be delicious.
For the shortbread, I baked a very small batch of the traditional 1:2:3 (sugar:butter:flour) shortbread recipe, using half an ounce per part (if that makes sense...), making it very flat for crumbling.
To make the swirl, I filled the freezing tub as follows: layer of ice-cream, layer of crumbles, layer of ice-cream, layer of chocolate sauce, etc., until I ran out of ice-cream. Excess sauce and crumbles can be used for decorating on serving the ice-cream. I then swirled it all up with the blade of a table knife. I popped it in the freezer to freeze overnight.
As with any ice-cream, it needed to be left on the kitchen counter to temper so it was scoopable, but it is absolutely delicious. I still have some in the freezer, and I'm permitting myself a scoop every few days. I've been so good over the last two weeks: I've lost 5 and a half pounds!