Make crust: In a food processor, pulse flour, sugar, and salt until combined. Add butter and pulse until mixture resembles coarse meal, with a few pea-size pieces of butter remaining. Add egg yolk. With machine running, add ice water. Pulse just until dough is crumbly but holds together when squeezed. Wrap dough in plastic and flatten into a disk. Refrigerate until firm, 1 hour (or up to overnight).
Preheat oven to 350 degrees. On a lightly floured work surface, roll out dough to a 14-inch round. Place in an 11-inch fluted tart pan with a removable bottom; trim any excess. Prick dough all over with a fork. Freeze 15 minutes. Place a sheet of parchment paper over dough and fill with pie weights or dry beans. Bake until crust feels dry and flaky, 20 minutes. Remove parchment and weights; bake until crust is light golden brown, 8 to 10 minutes. Let cool completely in pan on a wire rack.
Meanwhile, make filling: In a large bowl, whisk together butter, maple syrup, eggs, cream, salt, pumpkin puree, and lemon zest. Fold in breadcrumbs and pour filling into tart shell. Bake until filling is set and a toothpick inserted in center comes out clean, 40 to 45 minutes. Let cool 30 minutes in pan on wire rack before serving.
Wrap tart in plastic. Store at room temperature, up to 1 day, or refrigerate, up to 3 days.