A drink named "The grand margarita" became a famous upgrade on the traditional margarita in the 1980s. Also known as a "Cadillac Margarita," its recipe swaps out triple sec for Grand Marnier.
Just whip it out of the freezer 10 minutes before slicing or scooping. I like to add a little extra Grand Marnier to the mix. If you have fresh berries, great, otherwise frozen are just fine.