1. Place all fruit in a bowl and mix in frozen orange juice concentrate.
2. In a blender, combine yogurt, ricotta, ginger, cinnamon and vanilla.
3. Portion the fruit into dessert bowls, top each with yogurt-ricotta sauce and garnish with a walnut half.
4. Other fruits may be substituted, such as melon, kiwi, strawberries, blueberries, pears or pineapple. The fruit medley may also be served without topping.