To prepare the crust, place 1 cup flour, 2 tablespoons sugar, 2 teaspoons lemon zest and a pinch of salt in a food processor or bowl. Mix well. Add 6 tablespoons cold butter, pulsing until mixture looks like coarse meal. Add vanilla extract and 2 tablespoons water and pulse until dough forms a ball. Wrap in plastic wrap and chill at least 30 minutes.
Preheat oven to 375F. Roll dough out and cut into 4 circles 1-inch larger than your tart pans or 12 inches if using a 10 inch tart pan. Place dough in pans. Crimp edges. Bake for 15 minutes if individual tart shells or 30 minutes if one large one. Cool
Meanwhile, make the lemon curd: Whisk together eggs, egg yolks and sugar, in a medium saucepan. Whisk in lemon zest and juice. Cook over medium-low heat, stirring constantly until thick enough to coat the back of a wooden spoon, about 7 minutes. Remove from heat and whisk in butter, 1 piece at a time.
Pour filling into cooled tart shell. Bake until filling is browned, slightly puffed, and set, about 15-30 minutes. Let cool completely.