To begin, ensure that your blender is clean and dry. Make sure you washed it after your previous use, so that no residual food items are sticking to the walls or blades, as these will taint your milkshakes, and give them an odd, unpleasant odour and taste.
Now, start by adding two generous cups of coffee ice cream to the blender. There are no hard and fast rules for what sort of coffee ice cream you should use. This could be a regular coffee ice cream from any brand you prefer – you can also use coffee ice cream that is studded with chocolate or mocha chips, as these will add a nice texture to the shake once they are blended and broken into tiny bits.
Next, add in half a tablespoon of Dutch process cocoa powder – this tends to be smoother and finer in texture as compared to regular cocoa powder, and is generally used in drinks like hot cocoa and in milkshakes, etc. Once you have added this in, proceed to pour in the milk – it is essential to use whole milk, as this will make for a thicker, creamier shake. Skim or low-fat milk will just make the shake watery and thin.
Once these ingredients have been added to the blender, pour in the cold coffee. It is best if you brew a fresh pot of coffee, allow it to sit until it reaches room temperature, then pour it out into a cup and slide this into the refrigerator to chill.
Sprinkle in the cinnamon, after the cold coffee, and then put the lid on the blender. Blend it until the shake becomes thick, smooth, and creamy in consistency. Pour it out into tall glasses, top with whipped cream and chocolate sauce, insert straws, and serve.