The only thing you need to know before you attempt this recipe is that because ovens run somewhat differently from one another, your baking time may vary widely from mine. If you really get into a jam where you feel like you’ve been waiting forever, and your meringues still aren’t quite done, you can always turn the oven back on, let it heat up again, and then shut it off once more to wait for an additional 30 minutes or so — that should do the trick.
4 large egg whites, at room temperature
1 cup plus 2 tablespoons pure cane sugar
2 tsp. pure vanilla extract
zest of 1 lemon
1 tsp. cream of tartar
1 jar (about 10.5 oz) prepared lemon curd — make sure you grab a high-quality brand without any odd, junky ingredients.
Preheat your oven to 350 degrees. Line two baking sheets with parchment paper.
In a large mixer bowl, combine the egg whites and 1/4 cup of the sugar. Whip with an electric mixer (hand-held or stand) until frothy. Continue whipping and adding the remaining sugar gradually until the egg whites have reached soft peaks and all the sugar is incorporated.
Add the vanilla, lemon zest, and cream of tartar to the egg whites and continue whipping at high speed until the egg whites are stiff and glossy. Using two spoons, scoop the meringue out into small mounds on the prepared baking sheets, about 1 inch apart from each other (you’ll get between 24 and 36 meringues).
Use the handle of a small spoon to form a well in the center of each meringue, as if you’re making them into nests. The indentations will hold the lemon curd after the meringues are baked. Turn off the oven and put the meringues in to bake. Set a timer for 90 minutes. After 90 minutes, check the meringues and, if they’re not dry and crisp all over, switch the positions of the baking sheets in the oven. Continue allowing the meringues to sit in the warm oven for another 30-60 minutes, until they are perfectly crisp and dry (make sure to check the bottoms of the indentations, which are often the last part to become fully dry).
Remove the meringues from the oven and gently pull them off of the parchment paper. Allow them to cool for a few minutes, then fill the indentations with lemon curd — about 1/2 tsp. per cookie should suffice. Let them cool completely before serving.