Whisk the flour, sugar, and salt together in a medium bowl. Using a pastry cutter or 2 forks, cut in the butter until the mixture resembles coarse pea-sized crumbs. Add the water and stir until the flour is moistened. Add 1–2 more Tablespoons of water if the dough seems dry. Turn the dough out onto a lightly floured work surface and, using your hands, work the dough into a ball. Flatten it into a thick disc. Wrap the dough disc in plastic wrap or parchment paper and refrigerate it for at least 1 hour, and up to 3 days.

Peel, halve lengthwise, and scoop out the seeded core of the pears. Remove the stem, including the bottom part of the stem. Place the pears in a medium bowl, and toss gently with lemon/orange juice, cinnamon, nutmeg, and ginger, until evenly coated. Place the bowl in the refrigerator until you’re ready to use the pears.

Melt the butter in a 10-inch oven-safe skillet over medium heat, or use a heavy-duty medium saucepan. Once the butter has melted, whisk in the brown sugar. At first it will look very separated, like it doesn’t want to combine, but that’s ok. Just keep whisking. Cook, whisking occasionally, for 3 minutes. Remove from heat and let cool for a few minutes while you roll out the crust. (If you used a saucepan for the caramel, pour it into an ungreased 9 or 10-inch pie dish.)

Preheat oven to 400°F (204°C).

Roll out the chilled dough into a circle about 11–12 inches in diameter (it doesn’t have to be perfect!). Arrange the pears, cut-side up, in the skillet. Drape the pastry crust round over top of the pears. Gently tuck in the edges of the crust around the pears with a spoon. Dock (prick) the crust with a fork, to allow steam to escape.

Bake for 20 minutes, then keeping the tarte tatin in the oven, reduce the temperature to 375°F (191°C) and bake for 25 more minutes, or until the crust is golden-brown.

Allow to cool for 10 minutes on a cooling rack, and then carefully invert the tart onto a large serving plate or platter. I recommend doing this over the sink to catch any possible spills. Use extreme caution as the caramel sauce and fruit are very, very hot.

Slice and serve warm or at room temperature with vanilla ice cream, if desired. Cover and store leftover pear tarte tatin in the refrigerator for up to 4 days.