Preheat oven to 375 degrees Fahrenheit.

Lay nectarine halves in a single layer on a lined baking tray, facing down. Sprinkle cinnamon and sugar, spray with oil, and bake for 20 minutes until soft.

Add orange juice, pineapple juice, mango, sour cream, and baked nectarine halves to a blender and pulse until smooth. Taste and add sugar according to desired sweetness.

Fill up a two-pound (2/3 quart/liter) container with the fruit mixture and set aside.

Divide the remaining mixture between two additional containers. Blend frozen strawberries into one and frozen blueberries into the other. You should now have three colors of the fruit blend.

To serve, start with one color as the base, then add the second color to the center, and follow that with the third. Top with fresh berries or maraschino cherries and mint leaves.