Instructions

1. Arrange a rack in the middle of the oven and heat the oven to 400°F. Remove dough from refrigerator and let sit at room temperature while you prepare the filling.
2. Add 1/4 cup packed light brown sugar, 1 tablespoon cornstarch, 1/2 teaspoon ground cinnamon, 1/4 ground ginger, and 1/4 teaspoon kosher salt in a large bowl and stir to combine.
3. Finely grate the zest of 1/2 medium lemon until you have 1/2 teaspoon. Juice the lemon until you have 1 tablespoon. Add both to the bowl with the sugar mixture and stir to combine.
4. Peel, halve, core, and thinly slice 1 1/2 pounds Anjou or Bosc pears. Add to the bowl with the sugar mixture and gently toss to coat.
5. Unwrap the dough and place on a lightly floured sheet of parchment paper. Lightly flour a rolling pin and roll the dough into a 12-inch round about 1/8-inch thick. Slide the parchment and the dough onto a baking sheet.
6. Arrange the pears on the dough in a concentric circle, starting at the outside and leaving a 2-inch border and then working your way in towards the center, overlapping the slices about halfway. Drizzle any remaining juices in the bowl over the pears. Gently fold the edges of the dough over the filling, pleating it about every 2 inches.
7. Cut 2 tablespoons unsalted butter into 8 pieces. Place 1 large egg and 1 tablespoon of the water in a small bowl and beat with a fork to combine.
8. Scatter the butter over the filling. Brush the crust with the egg wash and sprinkle with 2 teaspoons coarse sugar if desired.
9. Bake until the crust is a deep golden-brown, the juices are bubbling, and the fruit is tender, 35 to 40 minutes. Slide the parchment with the galette on it onto a wire rack and let cool completely.
10. Place 1 tablespoon light-colored jam and the remaining 1 teaspoon water in a small bowl and stir to combine. Brush the filling with the glaze. Cut the galette into wedges and serve.