In a separate bowl, whisk together the all-purpose flour and the salt. Set aside.
Beat the unsalted butter and white granulated sugar together on medium-high speed until creamy.
Add the eggs and pure vanilla extract until combined.
Slow the mixer speed down to low and gradually add the all-purpose flour mixture until just combined.
Shape the dough into a ball, wrap in plastic wrap and place in the refrigerator for 60 minutes.
Preheat the oven to 400 degrees F.
Line 2 baking sheets with parchment paper.
Turn the dough out onto a lightly floured work surface and roll out. Use an egg shaped cookie cutter to cut out solid egg-shaped cookies. Place on one of the baking sheets.
Cut out another set of egg-shaped cookies, then use a small round cutter to create a hole in the center.
Place the cutout cookies on the other baking sheet.
Place the baking sheets in the oven and bake 10 minutes. Check them after 5 minutes.
Remove the cookies from the oven. Transfer to cooling racks, separating the solid and the cutout cookies on two different racks. Let cool completely. Reserve the baking sheets, line with new sheets of parchment paper.
When the cookies have cooled completely. Whisk together the powdered sugar with water, adding one tablespoon at a time until the consistency is thin enough to pour.
If the mixture becomes too thin, add some more powdered sugar, one tablespoon at a time until the consistency is right.
Place the cooling rack with the cutouts over the baking sheet with the parchment paper.
Dip the cutout cookies into the sugar glaze and tap gently on the side of the bowl to let the excess icing run off.
Place the glazed cutout cookie back on the cooling rack. Repeat until all the cutout cookies have been glazed. Let the glaze dry completely before handling.
Brush the completely cooled solid egg-shaped cookies with a thick layer of lemon curd. Top the cookie with the glazed cutout cookie and place back on the cooling rack.
When all the cookies have been mated, let them sit for at least one hour to dry completely before plating and serving.