Micheal, Your New England heritage is showing thru with that recipe. I will never forget ordering a Chocolate Shake when I first arrived at Ft Devens,MA back in 1960. I received a cup full of what Micheal just "made". Thin whipped flavored milk. Where was the Ice-Cream I asked???? Oh, You want a Frappe, said the young lady. I learned the difference rather quickly!
This particular fountain item is the sterotype for all the debate over the influence of the 'chain' places vs the regional or local menu items. Shortly after I first arrived in New England we saw the influx of the FF places (you know the names). The term "Shake" was used to describe what had been a "Frappe" and "Soda" seemed to replace "Tonic" rather quickly as well. The "ER" was added to "Hamburg" and "Franfurt". This all happened in a few short years in the early 1960's.
The cultural impact took a bit longer. In 1963 I went into a McDonalds in Lawrence, MA on a Friday Evening and ordered a couple of Cheeseburgs. The girl at the counter looked at me in horror. She tried to remind me, politely, that it was "FRIDAY NIGHT", which went right over my Southern Californian, Non-Catholic head. The PC thing to order were the Fish-Sandwiches at that point...but I was not attuned to the fine points of "CYA" at the time !!!
For me it is a Black and White shake... Some Whole-Milk, 2 Large scoops of Vanila Ice Cream and one scoop of Chocolate Ice Cream (Hard Ice Cream as opposed to Soft-Serve). A couple of fountain squirts of Hot Fudge (Chocolate syrup is a poor second choice) and then onto the mixer-machine. Pour a 12 oz glass full, but their better be enough in the Mixer cup to refill that glass one (full) time. Top with a squirt of Whipped cream and a Cherry.