Frozen diced mango helps keep preparation to a minimum for this anytime smoothie. Blend with buttermilk, sugar and vanilla. Substitute other frozen fruits, like peaches, for fun variety.
Process mango, 1 cup buttermilk, sugar, and vanilla in a blender until smooth. Add up to 2/3 cup more buttermilk, 1 Tbsp. at a time, processing until desired consistency is reached. Stir in cardamom, if desired. Serve immediately.