Preheat oven to 350°F (175°C). Grease a 9x13-inch baking dish and line it with aluminum foil, leaving overhang for lifting out the dessert. Grease the foil.

Combine 2 cups flour, 1 cup confectioners' sugar, and 1 tablespoon lemon zest in a bowl. Mash butter into the mixture until it resembles fine crumbs. Press crumb mixture into the bottom of the greased dish.

Bake crust in preheated oven until golden brown, about 15 to 20 minutes.

Beat eggs in a mixer until lightened in color.

Mix white sugar, 1/4 cup flour, and baking powder in a separate bowl. Beat this mixture into the eggs until fully incorporated.

Stir in lemon juice and lemon zest to the egg mixture. Pour filling over the baked crust.

Bake in preheated oven until set in the middle and slightly golden around edges, about 25 minutes.

Cool the pastry in the pan until just warm. Dust with confectioners' sugar, then cool completely.