Combine the blueberries, raspberries, strawberries and maple syrup in a bowl until well combined. Let stand 5 minutes. Meanwhile, pulse the confectioners' sugar, orange zest, cinnamon and ricotta in a food processor until smooth. In each of 4 parfait glasses, alternately layer the berry mixture with the ricotta mixture, ending with the berries. Top each with 1 teaspoon of toasted walnuts.