To make the cake: Preheat the oven to 350 degrees. Butter two 9-inch round cake pans. Flour pans, tapping out excess; set aside. In a medium bowl sift together the flour, baking powder, and salt; set aside.
In the bowl of an electric mixer fitted with the paddle attachment, beat together the butter and sugar until light and fluffy, about 2 minutes. Add the eggs, one at a time, beating to combine after each addition. Beat in the vanilla and the lemon zest. Add the flour mixture, alternating with the milk, beginning and ending with the flour mixture. Beat until just combined.
Divide batter between prepared pans. Bake until a cake tester inserted in the center comes out clean, 30 to 40 minutes. Remove from oven, and let stand in pans until cool, about 1 1/2 hours.
Remove cakes from pans. Using a serrated knife, trim tops of cakes. Slice each cake horizontally into 3 layers. Place one layer on a serving platter. Spread with 1/4 cup lemon curd. Top with second layer of cake. Spread with 1/4 cup curd. Repeat with remaining cake and curd, finishing with a layer of cake. Transfer to refrigerator until ready to use, at least 2 hours.
Remove cake from refrigerator. Spread a thin even layer of meringue over sides of cake. Mound the remaining meringue on top of cake. Use a handheld torch to brown meringue.