An approachable French upside‑down tart featuring warmly spiced, caramelized pears nestled under a flaky pie crust, flipped to reveal glossy fruit bathed in brown‑sugar butter caramel.
Make the crust: In a medium bowl, whisk flour, granulated sugar, and salt.
Cut in the cold cubed butter with a pastry cutter or 2 forks until coarse pea‑sized crumbs form.
Drizzle in ice‑cold water; stir until the dough is moistened and comes together (add 1–2 more tablespoons water if needed).
Turn dough onto a lightly floured surface, bring together, flatten into a thick disc, wrap, and refrigerate at least 1 hour (up to 3 days).
Prepare the pears: Peel, halve lengthwise, remove stems, and scoop out the cores. Toss gently with lemon/orange juice, cinnamon, nutmeg, and ginger until evenly coated; set aside.
Make the caramel: In a 10‑inch oven‑safe skillet (or saucepan), cook the butter and brown sugar together over medium heat, stirring until melted, combined, and beginning to thicken. Remove from heat. If using a saucepan, pour the caramel into a pie dish.
Arrange the pears core‑side up over the hot caramel, packing them in tightly.
Roll the chilled dough into a round slightly larger than the skillet; drape over the pears. Gently tuck the edges down around the fruit and dock the crust with a fork to vent.
Bake until the crust is deeply golden and baked through and the caramel is bubbling at the edges.
Cool about 10 minutes, then carefully invert the warm tart onto a large plate or serving platter.
Serve warm, optionally with vanilla ice cream or whipped cream.