Preheat your oven to 325°F (160°C).
Line an 8x8 inch baking pan with parchment paper and lightly spray it with non-stick spray; set aside.
In a small saucepan over medium-low heat, melt the butter until it just starts to brown—be careful not to overdo it!
In a large bowl, mix the browned butter, brown sugar, and honey until smooth. Add the egg and yolk, whisking until combined.
Stir in 1 teaspoon of salt and all the flour, being careful not to overmix!
Pour the batter into the prepared pan, then sprinkle with the remaining salt and chopped pistachios.
Bake for 23-25 minutes, until the edges are set and the top is golden, but the center remains slightly soft.
Let the bars cool in the pan for 10 minutes, then transfer to a cooling rack to cool completely. Once cool, cut into small squares and enjoy!