CREAM CHEESE DOUGH:
- 1/2 cup cream cheese, cold, cut in chunks
- 1/2 cup butter, cold, cut into chunks
- 1/2 cup flour
- 4 elephant heart plums, skins removed and pitted
- 3 tablespoons granulated sugar
- 1/8 teaspoon ground cinnamon
- 1/4 cup creme fraiche
- 1 egg, beaten
- Confectioners' sugar, for dusting
- 1/4 cup simple syrup (equal parts warm water and sugar heated until the sugar is dissolved)
- 1/4 cup freshly squeezed lemon juice
- 2 teaspoons rosemary leaves
MAPLE MASCARPONE CREAM:
- 1 1/2 cup Mascarpone cream
- 1/2 cup heavy cream
- 1/3 cup maple syrup
Make the tart shells: In a medium bowl, combine the cream cheese, butter, and flour until it just comes together. (There should still be streaks of cream cheese.) Remove the dough from the bowl, pat into a disc, cover with plastic wrap, and refrigerate for at least 1 hour. Roll out the dough into 1/8-inch thickness and cut into 6 (3-inch circles). Refrigerate on a parchment-lined sheet pan for 15 minutes.
Make the filling: Dice 2 of the plums and toss together with 2 tablespoons of the granulated sugar, the cinnamon, and creme fraiche.
Assemble the tarts: Brush the dough lightly with the beaten egg and spoon a generous tablespoon of the filling in the center of each circle. Lift up the edges of the tart and pinch 3 points of the tart about halfway to the filling to form the sides of the crust. Refrigerate for 30 minutes. Brush the edges of the crust with egg and sprinkle lightly with the remaining 1 tablespoon granulated sugar. Pinch the dough again to make sure it is tightly sealed and freeze for 10 minutes. Remove the tarts from the freezer and immediately bake at 350 degrees for 20 to 25 minutes, or until golden brown. Let cool slightly and dust with confectioners' sugar.