Add 2 cups of vanilla ice cream and ½ cup of whole milk into a blender.
Toss in the blueberries and raspberries.
Blend until smooth. If the texture is too thick, add a splash more milk.
For a brighter purple, add a drop of food coloring and blend again.
Pour the shake into a tall glass, add a swirl of whipped cream on top, and enjoy it with a playful straw.
