Not exactly a shake, but you can use two packets of hot chocolate mix with heavy cream instead of milk or water.
A pint of cream and two packets should be around 1,900-1,920 calories (not an even 1,920 as some sticks to the side of the glass, all within 20 fl. oz.
If that seems too thick or heavy, can start off with half and half, moving to cream later.
Using a straw will help you suck it down even easier.
5 years