Pear & Cranberry Crumble Top Slab Pie PIECRUST 3 3/4 cups all-purpose flour, plus more for rolling 2 1/2 teaspoons coarse salt 1 1/2 teaspoons granulated sugar 3 sticks cold unsalted butter, cut into small pieces 1/2 cup ice water, plus more if needed CRUMBLE TOPPING 1 1/2 cups pecan halves, toasted and chopped (about 1 1/2 cups) 1 1/2 cups all-purpose flour 1 cup old-fashioned rolled oats 1 1/2 teaspoons coarse salt 2 sticks unsalted butter, softened 1/2 cup packed light-brown sugar 1 cup granulated sugar FILLING 5 1/4 pounds firm-ripe Bosc or Anjou pears (about 12), peeled, cored, and cut into 1/2-inch wedges 4 teaspoons fresh lemon juice 1 vanilla bean, seeds scraped 1 cup granulated sugar 1/4 cup all-purpose flour 1/2 teaspoon coarse salt 1 1/4 teaspoons ground cinnamon 2 cups fresh or unthawed frozen cranberries Piecrust: Place flour, salt, and sugar in a food processor and pulse to combine. Add butter and pulse until mixture resembles coarse meal with some blueberry-size clumps.