Lime Squares with Pistachio-Graham Cracker Crust

These lime bars are very refreshing. The pistachio crust makes them different, it's a surprising combination.
Ingredients:

• 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 grated lime zest
• For the Filling:
• 2 large egg yolks
• 1 can (14 ounces) sweetened condensed milk
• 1/2 cup fresh lime juice (I haven't tried non-fresh lime juice, but i can't imagine that it would change them that much....)
  

1. 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.
2. 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.
3. 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.
4. 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.