In a large bowl stir together flour, the 1/3 cup sugar, and 2 teaspoons shredded lemon peel. Using a pastry blender, cut in the 1/2 cup cold butter until mixture is crumbly. Add 2 egg yolks and 2 tablespoons water to flour mixture; stir with a fork to combine. Gently knead the dough just until a ball forms. If necessary, cover with plastic wrap; chill for 30 to 60 minutes or until easy to handle.
Preheat oven to 375 degrees F. Divide chilled dough into 12 pieces. Press one piece onto bottom and halfway up the sides of a 3-inch muffin cup; repeat with remaining pieces. Bake in the preheated oven for 10 minutes or until golden. Cool in muffin cups for 10 minutes. Remove and arrange in a 15x10x1-inch baking pan. Reduce oven temperature to 350 degrees F.
In a small bowl whisk together the egg yolk, milk, lemon juice, and salt; set aside.
In a small saucepan, stir together the 1/2 cup sugar and the cornstarch. Stir in 1 teaspoon shredded lemon peel, the lemon juice, 3 tablespoons water, and 2 tablespoons butter. Cook and stir over medium heat until thickened and bubbly. Remove from heat.
Stir about half of the mixture into the 3 egg yolks. Return all mixture to saucepan. Return to heat. Cook and stir for 2 minutes more. Cover to keep warm.
For meringue, in a medium bowl beat egg whites, vanilla, and cream of tartar with electric mixer on medium speed until soft peaks form. Gradually add 1/2 cup sugar, beating on high speed until stiff peaks form.
To assemble, spoon about 1 tablespoon lemon filling into each baked crust; top with 1 tablespoon lemon curd. Top each generously with meringue, spreading to edges of crusts. Sift powdered sugar over tarts. Bake for 12 minutes or until golden. Cool in pan on a wire rack. Cover loosely with foil and chill within 1 hour. Drizzle the chilled tarts with honey before serving, if desired.