Lime Curd Thumbprint Cookies

I love citrus curds. Lemon, lime - even orange. They're velvety, slightly sweet, quite tart and the perfect topping for a wire variety of baked goods.
I am not going to claim that this is the best use for a curd because I still think that my spoon is the finest vehicle, but it is a darn nice way to eat it. A crisp buttery cookie makes a great shell for the lime curd, though, like all cookies with moist fillings, the crispness does not last for more than a day. It gives way to a moist, buttery, crumbly cookie that melds into the curd in a very appealing way.
I used Alice Medrich's recipe for lemon curd and simply substituted lime juice for lemon juice. I didn't believe that a curd without butter would work, either, but it's great! Tanvi adapted the recipe to a lighter lemon curd a while back, reducing the sugar from the original. I advise against reducing the sugar in this recipe if you are going to use limes, unless your limes are far less tart than mine. If you have a strong aversion to tartness, you can add one more tablespoon of sugar. Next time, I think that I will stir some lime zest into my curd, which I forgot to do this time, to emphasize the fact that this is lime and not lemon. The vanilla flavor came through wonderfully after refrigeration.
The cookies are easy and versatile. I made them in the "thumbprint" style of cookie here, but you can roll them out or refrigerate the dough and slice them later. The dough produces nice, crisp cookies when unadorned. You can also use jam when making little mini-tarts here, but the lime curd makes them zesty, bright and addictive. esides, you can eat more than one tart and feel good about it. How often can you say that?

Lighter Lime Curd
(adapted from Chocolate and the Art of Low Fat Desserts)
1/3 cup strained, fresh lime juice
1-2 tsp lime zest
5 tbsp sugar
1 egg, room temperature
1/2 tsp vanilla extract

In a small sauce pan, over medium heat, dissolve sugar into lime juice. Add zest.
Lightly beat egg in a small/medium bowl. Whisking constantly, slowly pour lime/sugar syrup into the egg. Beat for 2 minutes (only 1 if you're using a mixer), then transfer back into the saucepan. Heat over low heat, stirring constantly, until it just starts to bubble at the edges. Remove from heat and stir in vanilla
Transfer to a small container and store in the fridge.
Makes 2/3 cup.

Thumbprint Cookies
¼ cup butter, room temperature
½ cup sugar
pinch salt
1 tsp vanilla
3 tbsp milk
¼ cup cornstarch
1 ¼ cup ap flour
Lime curd (above) or jam

Preheat oven to 375F. Line a baking sheet with parchment paper.
Cream together butter, sugar and salt. Beat in vanilla, milk and cornstarch. Stir in flour until just combined.
Roll into 1 inch balls and roll in coarse sugar. Place on baking sheet and make a shallow indentation with your thumb. Fill indentation with a bit of lime curd or jam.
Bake tarts for 12-13 minutes, until cookies just start to brown.
Cool on a wire rack.
Makes about 2 dozen.