Notes: If making ahead, bake crust and filling, let cool, cover, and chill up to 1 day. Then top with figs.
1. To make crust: In a food processor or a bowl, combine flour, granulated sugar, butter, and lemon peel. Whirl or rub with your fingers until mixture has texture of fine crumbs. Add egg yolk and whirl or stir with a fork until a dough forms. Pat dough into a ball, then press evenly over bottom and up sides of a 10-inch tart pan with removable rim.
2. Bake crust in a 300° oven until golden, about 30 minutes.
3. Meanwhile, make filling: In a food processor or blender, whirl eggs, granulated sugar, lemon slices, flour, and butter until lemon is finely chopped.
4. Pour filling into hot crust. Continue to bake until filling is firm when pan is gently shaken, about 12 minutes. Let tart cool.
5. Cut figs into thin slices and arrange neatly over tart filling. Sprinkle figs with lemon juice and dust with powdered sugar. Cut tart into wedges.