In Australia we have a distinction between a milkshake and a thickshake.
Milkshakes have only one scoop of icecream, they are mainly frothy milk. Generally older folks choose them - I'm in my 50s and we were about the first of the thick shake generation growing up in the 1970s.
Thick shakes are either made with several scoops of ice cream, or made from junky soft serve.
I used to work for a restaurant that was famous for its shakes amongst other things. When you could get a milkshake for $3 in other places, ours were $6. Here's why:
5 scoops of ice cream. (#30 scoop, or about a slightly heaped soup spoon full)
2 shots of flavouring syrup (from memory each shot was 30 ml.)
3/4 cup of milk
a generous dash of cream
2 teaspoons of malt powder
Whizz in spindle milkshake mixer for several minutes.(ours were Woodson, I got good at rebuilding them with new bearings and brushes)
If the motor isn't smoking, you haven't used enough ice cream. Also the straw should stand up in the drink.
for some reason strawberry flavour whipped up more and would often overflow the mixer cup.
My own special variation was 1 shot of vanilla syrup and 2 shots of espresso coffee.
Serve in a pint glass. NO disposable take-away containers, they are the work of the Devil.
we used to have a group of women who met at our restaurant once a month after weight watchers. They would order our shakes with skim milk. I used to tell them the ingredients and say "with all that icecream and extra cream, you want skinny milk?" but they would say "yes, use skinny milk", as if a bit if skim milk had magic powers to undo the cream, icecream and flavour syrup.
Later I devised my own banana smoothie:
in a blender (mine is an old National, from before they changed their name to Panasonic) add:
I large (or 2 small) ripe banana
several scoops of icecream - 5 or 6
a dash of honey
a dash of cream
a shake of cinnamon powder
a tiny bit of cardamom powder
Whizz till the blender catches fire.
serve in pint glass.
Sadly dairy no longer agrees with me so the above is off my menu.
Enjoy it while you can.
Chris.