Crostata Di Zucca Gialla E Ricotta (Buttercup Squash And Ricotta Crostata)

Buttercup squash is not as well known as other varieties of winter squash such as butternut or acorn — but it should be. Buttercup is squat and round with a hard, dark-green, striped rind. Beneath that rind is bright orange flesh that is smooth, dense and sweet when cooked. Look for buttercup squash at farmers markets and well-stocked supermarkets through fall and into winter. Be sure to use good-quality ricotta, not the grainy mass-produced stuff you find in most dairy cases — it makes a difference.

Makes one 9-inch lattice-top crostata

8 ounces whole cow's milk ricotta cheese

8 ounces cooked buttercup squash, pureed (see Cook's Note below)

3/4 cup confectioner's sugar, plus more for dusting

2 large eggs, separated

2 tablespoons dark rum or brandy

1/2 teaspoon pure vanilla extract

1/4 teaspoon cinnamon

1/8 teaspoon salt

1/8 teaspoon cream of tartar

Whipped cream for serving

Cut the dough disk into 2 portions, one slightly larger than the other. Rewrap the smaller portion and refrigerate. On a lightly floured surface, roll out the larger portion into an 11-inch round about 1/8 inch thick or slightly thicker. Carefully wrap the dough around the rolling pin and drape it over a 9-inch fluted tart pan with a removable bottom. Gently press the dough into the bottom and up the sides of the pan. Use the rolling pin or the flat of your hand to press around the perimeter of the pan to cut off any excess dough. Put the lined tart pan in the refrigerator to chill for 30 minutes.

Heat the oven to 350 degrees.

While the dough is chilling, make the filling. In a large bowl, beat together the ricotta cheese and buttercup squash. Beat in the sugar, and then the egg yolks, rum, vanilla and cinnamon.

In a separate bowl, using clean beaters, beat the egg whites with the salt and cream of tartar until stiff peaks form. Gently fold the egg whites into the ricotta-squash mixture.

Remove the tart shell from the refrigerator. Gently spoon the filling into the shell and smooth it with a spatula. Roll out the remaining dough portion into a 10-inch round about 1/8 inch thick or slightly thicker, and cut it into 3/4-inch-wide strips with a fluted pastry wheel. Carefully place the strips over the filling in a lattice pattern, gently pressing the ends of the strips into the metal rim of the tart pan with the palm of your hand to cut off the excess. If you like, you can arrange more strips around the outer rim of the pan to form a border. Press these into the metal rim to cut off any excess dough.

Bake the crostata for 50 to 60 minutes, until the crust is golden and the filling is puffed and just set. Remove from the oven and place it on a wire rack to cool for about 20 minutes. Remove the fluted rim of the tart pan and transfer the crostata to a decorative serving platter. Serve warm with a dollop of whipped cream on top of each serving.

Cook's Note: To cook buttercup squash, use a large, sturdy chef's knife to split the squash in half and scoop out the seeds. Rub the flesh with a small amount of vegetable oil and set the halves, cut-side-down, on a rimmed baking sheet. Bake at 375 degrees for 45 to 60 minutes or until you can easily pierce through the rind with a fork. Remove from the oven and let cool. Scoop out the flesh and measure out 8 ounces. Reserve the rest for use in other recipes (I use it to make squash pancakes and squash cornbread.)