Ingredients

• 1/2 stick unsalted butter, softened
• 1/2 cup packed light brown sugar
• 6 tablespoons all-purpose flour
• 1/4 teaspoon pure vanilla extract
• 1/8 teaspoon salt
• 1/8 teaspoon curry powder
• 1 large egg white
• 2 ounces fine-quality bittersweet chocolate, chopped
• 1/2 cup shelled roasted pistachios, chopped
• Equipment: a small offset spatula

Instructions

1. Preheat oven to 350°F with rack in middle. Line a large baking sheet with parchment.
2. Blend butter, brown sugar, flour, vanilla, salt, curry powder, and egg white in a food processor until smooth.
3. Glue parchment down with a dab of batter in each corner, then spread remaining batter evenly into a 14- by 10-inch rectangle (1/8-inch-thick) on parchment with spatula. Scatter chocolate and nuts evenly over batter, then bake until firm and golden-brown, 18 to 20 minutes. Transfer, still on parchment, to a rack to cool completely. Remove from paper, breaking into pieces.