Ingredients:

  • 225g unsalted European-style butter
  • 1 tbsp water
  • 200g dark brown sugar, packed
  • 100g granulated sugar
  • 1 large egg, room temperature
  • 1 egg yolk, room temperature
  • 2 tsp pure vanilla bean paste
  • 325g all-purpose flour
  • 1 tsp baking soda
  • 0.75 tsp fine sea salt
  • 150g roasted, salted pistachios, roughly chopped
  • 200g dark chocolate (60-70% cocoa), hand-chopped into chunks
  • 1 tbsp Maldon flaky sea salt

Instructions:

  1. Place the butter in a heavy-bottomed stainless steel saucepan over medium heat. Melt and continue cooking until the milk solids turn a deep mahogany brown and smell nutty. Immediately remove from heat.
  2. Whisk in 1 tablespoon of water to the brown butter to compensate for moisture loss during the browning process. Let cool until warm but not solidified.
  3. In a large bowl, combine the brown butter with dark brown sugar and granulated sugar. Whisk vigorously until the mixture is smooth and begins to lighten in color.
  4. Add the whole egg, egg yolk, and vanilla bean paste. Whisk for 2 minutes until the mixture is glossy and emulsified.
  5. Fold in the all-purpose flour, baking soda, and fine sea salt using a spatula until just a few streaks of flour remain.
  6. Gently fold in the chopped dark chocolate chunks and roasted pistachios.
  7. Scoop the dough into 60g balls and place on a tray. Cover and refrigerate for 2 to 24 hours. For the ultimate gourmet result with deep toffee flavor and fudgy texture, chill for 24 hours. A 2-hour chill is the minimum for a less greasy cookie.
  8. Preheat oven to 350°F (175°C). Arrange chilled dough balls on a parchment-lined baking sheet, spaced 3 inches apart.
  9. Bake for 10-12 minutes until the edges are golden and set, but the centers still look slightly underdone.
  10. Immediately sprinkle with Maldon flaky sea salt. Let cool on the pan for 10 minutes before transferring to a wire rack.