In a food processor, blend the ricotta cheese until light and fluffy, about 20 seconds. Add the jam and pulse until combined. Transfer to a large bowl.
In a separate bowl, using an electric hand mixer, beat the cream until thick. Add the powdered sugar and continue to beat until the cream holds stiff peaks. Working in batches, carefully fold the cream mixture into the ricotta mixture. Spoon the mousse into serving bowls and refrigerate for 1 hour. Garnish with fresh raspberries and serve.