From: Baking From my Home to Yours by Dorie Greenspan
1 1/2 teaspoons active dry yeast
1/3 cup whole milk, just warm to the touch
2 cups all purpose flour
3 tablespoons sugar
pinch of salt
5 tablespoons unsalted butter, melted and cooled
2 large eggs, at room temperature
1 teaspoon pure vanilla extract
about 14 ripe plums, preferably italian prune plums
2 tablespoons coarsely chopped walnuts, almonds (I used pecans)
3 tablespoons sugar
1/4 cup plum jam (I used sour cherry with rhubarb)
To make brioche: Put the yeast and warm milk in the bowl of a stand mixer and stir until the yeast is dissolved. Add the rest of the ingredients to the bowl, and fit the mixer with the dough hook, if you have one. Working on low speed, mix for a minute or two, just to get the ingredients together. Increase the mixer speed to medium and beat for 7 - 10 minutes, stopping a few times to scrape down the bowl and the hook, until the dough is stretchy and fairly smooth. The dough will seem fairly thin, more like a batter than a dough, and it may not be perfectly smooth - that is fine.
Transfer the dough to a clean bowl, cover with plastic wrap and leave it in a warm place until nearly doubled in size, 30 - 40 minutes.
Deflate the dough by lifting it up around the edges and letting it fall with a slap into the bowl. Cover the bowl again with plastic wrap and put it in the refrigerator. Slap the dough down in the bowl every 30 minutes until it stops rising, about 2 hours. Then if you’ve got the time, leave the dough in the refrigerator overnight - it will be tastier for the wait.
To Make The Tart: This tart looks prettiest when it’s made in a fluted pan. You can use either a 9-inch metal tart pan with a removable base or a porcelain baking dish, the kind sometimes called a quiche pan. Generously butter the pan.
Press the chilled dough into the bottom of the pan and up the sides - don’t worry if it’s not even. Cover the pan loosely with plastic wrap and refrigerate for 30 minutes.
While the dough is in the refrigerator, prepare the filling. Halve and pit the plums. If you are using large plums, cut each half into 2 or 3 slices. Set aside. Toss the chopped nuts with the sugar and set aside.
Remove the tart pan from the fridge and push and press the dough up the sides of the pan. Spoon the jam onto the dough and spread it over the bottom. Arrange the plums cut side down in a concentric circles covering the jam. Scatter over the nut mixture, and cover the tart lightly with a piece of plastic wrap. Place the tart on a baking sheet lined with parchment or a silicone mat and let it rest in a warm place for 30 minutes.
Meanwhile, center a rack in the oven and preheat the oven to 425 degrees F.
Uncover the tart and bake for 20 minutes. Cover it loosely with a foil tent to prevent the crust from getting too dark, and continue baking for another 10 minutes, or until the fruit juices are bubbling and the crust is firm and beautifully browned - it will sound hollow when tapped. Transfer the tart to a rack to cool for at least 45 minutes before serving.
