Lime Squares with Pistachio Graham-Cracker Crust

Recipe from Martha Stewart Everyday Food and Tested in Alice's Kitchen.
Makes 16 bars.

Every single time I've made these, they're gone in the wink of an eye and there are requests for the recipe. It's very easy to make, but it's nice enough for a fine dinner party or even a tea party. They look pretty on a paper doily and/or a glass cake stand. This creamy dessert is a cross between Key lime pie and traditional lemon bars. (For a lighter version, substitute fat-free sweetened condensed milk.) Serve these with one of the delicious fair trade hot teas or coffees. Lost River Market & Deli now has shelled pistachios in the bulk section.

FOR THE CRUST
4 tablespoons (1/2 stick) unsalted butter, melted and cooled, plus more for pan
2/3 cup shelled pistachios
1 cup (4 ounces) graham-cracker crumbs
1/4 cup sugar
1 tablespoons freshly grated lime zest
FOR THE FILLING
2 large egg yolks
1 can (14 ounces) sweetened condensed milk
1/2 cup fresh lime juice


To make the crust: Preheat oven to 350 degrees. Brush an 8-inch square baking dish with melted butter. Line bottom with parchment paper, leaving a 2-inch overhang on two sides.
In a food processor, finely grind pistachios with graham-cracker crumbs, sugar, and zest. Blend in butter. Press mixture into bottom and 1 inch up sides of prepared pan. Bake until lightly browned, 8 to 12 minutes. Cool crust, 30 minutes.

To make the filling: In a large bowl, whisk together egg yolks and condensed milk. Add lime juice; whisk until smooth. Pour filling into cooled crust; carefully spread to edges.
Bake until set, about 15 minutes. Cool in pan on rack; then chill at least 1 hour before serving. Using parchment paper overhang, lift out of pan, and transfer to a cutting board. With a serrated knife, cut into 16 squares, wiping knife with a damp kitchen towel between each cut. To store in refrigerator, cover with plastic wrap.