1. In bowl, beat together cream cheese, 1 tablespoon of the sugar and vanilla until smooth. Place orange juice in a small measuring cup and sprinkle gelatin over the top. Microwave on high for 15 seconds. Stir to dissolve. Set aside to cool slightly.
2. In a second medium-size bowl, beat cream until foamy. Gradually add remaining 3 tablespoons sugar; beat on high until soft peaks form. Beat in cooled gelatin; beat until stiff peaks form. Fold whipped cream into the cream cheese mixture. Cover and refrigerate for 15 minutes.
Tarts:3. Spread 1 teaspoon orange marmalade in each shell. Place a generous 1/3 cup of cream cheese mixture into each shell, mounding with a spatula.
4. Arrange fruit slices and berries on top. Refrigerate for at least 15 minutes until firm.
5. Heat remaining marmalade over low heat until melted. Allow to cool slightly. Brush tarts with the cooled marmalade. Chill for 30 minutes. Makes 6 tarts.