Dried Plum Tart and Balsamic Vinegar Tart / Crostata di Prugne al Balsamico

Directions

1. Preheat oven to 400°F.
2. Mix the flour, salt, butter, sugar and baking powder together in a bowl. Add the egg and vanilla to form a dough. If the dough is too dry, add a few drops of cold water. Flour your hands and press 2/3 of the dough into the bottom and sides of a 9-inch tart shell with removable bottom.Crumble the rest of the dough into small bits and set aside.
3. Bake the crust unfilled for about 10 to 12 minutes. Cool, set aside.
4. Place the plums in a saucepan and cover with 2/3-cup water. Bring to a boil, lower the heat and cook until they soften. Drain well and transfer them to a food processor and pulse until a thick, smooth paste is obtained. Transfer to a bowl.
5. Pour the vinegar into a separate pan and cook uncovered over medium heat until it thickens and is reduced to about 1/2 cup; it will be thick. Cool for 10 minutes.
6. Add the balsamic reduction to the plums along with the sugar, salt and zest. Combine well and transfer it to the cooled shell. Smooth the filling so it is even. Sprinkle the remaining dough bits evenly over the top and sprinkle 2 tablespoons coarse white sugar over the dough.
7. Lower the oven temperature to 375°F and bake for about 25 to 30 minutes or until the top crust is nicely browned.
8. Cool on a wire rack. Loosen the sides of the tart pan and carefully remove it. Place the tart on a serving dish. Cut into wedges.