Milkshake recipe

By weight (use a scale!):

One (1) part malted milk powder.

Three (3) parts milk.

Six (6) parts ice cream.

This makes a nice, medium thick, strongly malty shake.  From here you can adjust as per your own individual tastes.  The actual measurements I ended up with were 33 g malted milk, 100 g milk, and 200 g ice cream, because that was about the minimum for the stick blender to handle effectively.  It was a little on the large side, though.  I ended up splitting it with the wife.