Mascarpone and Roasted Plum Tart

Directions

1. Place the flour and 1 ½ tablespoon of sugar in the bowl of a food processor, pulse a few times to combine. Add the butter, and pulse 10 to 20 times, until the mixture resembles fine crumbs.
2. In a small bowl, lightly beat the egg yolk with the ice water. With food processor running, stream the egg mixture through the feed tube. Process until the dough holds together without being wet or sticky; don't process more than 30 seconds.
3. Scrape the dough onto a clean work surface. Form the dough into a ball, then flatten into a disk. Wrap in plastic. Chill at least 1 hour, up to 1 day.
4. Preheat the oven to 350 degrees. Cut each plum in half and remove the pit. Cut each half into four equal pieces. Place the plum pieces in a large bowl; add ½ cup of the sugar and the lemon juice. Split the vanilla bean down the center. Scrape the seeds from one half of vanilla bean; add to the plums and toss to coat.
5. Line a baking sheet with tin foil, and crimp 1 inch of each side up. Spread the plums in a single layer on the baking sheet. Roast for 10 to 15 minutes, until fork-tender and juices are bubbling. Let the plums cool about 10 minutes. Increase oven temperature to 400 degrees.
6. Carefully pinch up the tinfoil, and pour the juices into a small saucepan. Transfer the plums to a bowl and chill. Set the saucepan over medium-high heat and simmer until thickened and reduced to a ½ cup; set glaze aside.
7. Place the mascarpone, the remaining 2 tablespoon of sugar, Greek yogurt, and honey in a medium bowl. Scrape in seeds from the remaining half of the vanilla bean. Beat with a whisk until well-blended. Cover the bowl with plastic wrap and refrigerate.
8. Spray the tart pan with nonstick spray. Lightly dust a clean work surface with flour. Roll the dough out to a large circle (11 to 12 inches), about an eighth of an inch thick. Gently roll the circle over the rolling pin, transfer to the edge of the tart pan, and unroll into the pan. Gently press dough into the sides. Roll the rolling pin over the top to cut off any excess dough. Lightly prick the bottom and sides of the tart crust with the tines of a fork to prevent the dough from puffing during baking. Place the tart pan on a larger baking sheet and bake for 5 minutes. Reduce the oven temperature to 350 degrees and continue baking the crust for another 15 minutes, until the crust is lightly golden brown. Remove from the oven and place on a wire rack to cool.
9. Once the crust is fully cooled, spoon the mascarpone mixture into the crust and spread with an offset spatula or the back of a spoon until it forms an even coat. Arrange plum slices, slightly overlapping, in circles on top of the mascarpone filling. Lightly brush the glaze over the plums. Chill until ready to serve.