Gently roll the lemon along the counter, massaging it against the counter to help loosen the juice. Zest the lemon peel & squeeze the juice. Separate the eggs whites from the yolks and place the whites in a stand mixer.
To make the lemon curd, whisk ½ cup of sugar and arrowroot powder in a saucepan. Stir in 1-2 teaspoons of lemon zest, lemon juice, and water. Whisk over medium heat until thick and bubbly. Gradually temper the yolks by adding a bit of the thickened mixture.
Whisk the tempered yolks and lemon mixture and bring it to a simmer, stirring constantly. Cook and stir for an additional two minutes. Remove from the heat and stir in the chopped butter. The butter will create a glossier lemon curd! Chill at least one hour.
Going back to the egg whites in the stand mixer, it's time to make the meringue! Beat the egg whites, vanilla, and cream of tarter until stiff peaks form. Add the remaining 1 cup of sugar slowly, one tablespoon at a time while continuing to whisk at a high speed. The sugar will almost fully dissolve and stiff peaks will return. Fold in the remaining lemon zest.
Line a cookie sheet with parchment paper. Either trace a drinking glass on the parchment to create 12 uniform circles, or use a 2oz cookie scoop. The cookie scoop will create a rounded meringue, which is what I used. Piping the meringue into the circles will create more of a cloud-like texture, but can be a bit trickier to pull off.
Bake in a 300 degree preheated oven for thirty-five minutes. Turn the oven off and allow the meringues to gradually cool in a dry oven for one hour. Remove the meringues from the oven and gently peel off the parchment paper.
Spoon the lemon curd onto the meringues and add a bit more zest &; (optional) whipped topping. To keep for later, wait to add the curd to the meringues until just before serving.