Preheat oven to 250°F. Prepare cookie pans with parchment paper.
In small bowl, combine graham cracker crumbs and melted butter until thoroughly moistened. Press onto bottom and up sides of 9 inch tart pan. Refrigerate while making cookie topping.
In large bowl, whip Meringue Powder and water with electric mixer on high speed until soft peaks form. With mixer running, gradually add sugar. Whip until stiff peaks. Add vanilla and whip until well combined, scraping down bottom and sides of bowl as necessary.
Fill decorating bags prepared with a tip 1M, 1A and 4B with meringue. Pipe cookies 1-2 inches in diameter onto parchment-lined cookie pans, spacing 1 in. apart.
Bake smaller cookies for 35-40 minutes or until outsides of meringues feel firm and crisp. Bake larger cookies 45-50 minutes or until outside of meringues feel firm and crisp. Cool completely on pan. Peel cooled meringues off of parchment paper.
Spread lemon curd over crust. Top with meringue cookies.