The choice of fruit topping in this tart is yours. A mix of colors is fun; try red raspberries or strawberries, yellow peaches and a burst of green kiwi.
Place a fine-mesh stainless-steel sieve over a bowl and spoon in yogurt; place in the refrigerator to drain for 1 hour.
To make crust: Preheat oven to 300 degrees F. Coat a 10-inch tart pan with a removable bottom with cooking spray.
Lightly beat egg white in a small mixing bowl. Add cracker crumbs, butter and oil; blend with a fork to thoroughly combine. Press the mixture evenly into the prepared tart pan, extending the crust 1 inch up the pan sides. Bake until the crust is dry and crisp to the touch, about 10 minutes. Cool on a wire rack.
To make filling: Pour orange juice into a large heatproof bowl. Sprinkle gelatin over the surface and allow to soften for 2 minutes. Set the bowl in a skillet of simmering water and stir the orange juice to completely dissolve the gelatin. (Or use a microwave-safe bowl and heat in the microwave for about 25 seconds.) Beat cream and sugar to soft peaks in another bowl.
Fold the drained yogurt into the gelatin mixture with a rubber spatula. Gently fold in the whipped cream. Pour the filling into the cooled tart shell and chill in refrigerator until partially set, 20 to 30 minutes.
To assemble tart: If you plan to glaze the fruit, melt apricot preserves (or red currant jelly) in a small saucepan over low heat; if using preserves, strain through a fine sieve set over a small bowl. Set aside to cool slightly.
Trim or slice fruits as necessary and arrange on the chilled filling. Brush the fruits with the apricot (or currant) glaze, if using. Return the tart to the refrigerator to chill until the filling has set completely, about 4 hours.
1 other carbohydrate, 1 fat