Use a blender to grind up toffee or chocolate pieces into a fine dust. Later, combine all ingredients in a blender and blend until smooth. Pour into a glass and serve. For an added touch you can add whip cream on top.
For the whipped cream
In a bowl, combine all ingredients and beat until the cream holds soft peaks. Take small scoops of the whipped cream and place on top of the milkshake so it sits like a float.