1. Place the cherries and mangoes in two separate bowls and let them sit to thaw for about ten minutes.
2. Blend the cherries first: place the cherries and a 1/2 cup water in the blender and blend on high until smooth. Add the other 1/4 cup water if it seems too thick. Pour into a glass.
3. Rinse the blender pitcher and add the mango and the water. Blend on high until smooth. Add more water if needed. Pour into the glass on top of the cherry layer.