First, combine the instant coffee, sugar, and hot water and mix until it becomes stiff. Takes about 3 minutes. Stop when soft peaks form.
In a blender, add the vanilla ice cream, milk and then add the whipped coffee. Turn the blender on to combine the ingredients. Serve with whipped cream with cocoa powder sprinkled on top.
Notes
If you want your milkshake to come out thicker, add more ice cream. If thinner, add more milk.