Brown the butter. Melt the butter in a medium sized pan over medium heat. Once it melts, it will crackle, then become foamy – continue mixing the butter while this happens to prevent burning. The butter will go from melted to golden brown quickly, and you’ll know it’s almost done when the aroma of browned butter arrives. The whole process should take about 5 minutes! Once golden, remove from heat and transfer to a glass bowl. Let the butter cool for 30 minutes while you prep on the rest of the recipe.
Preheat oven to 350°F and line a baking tray with parchment paper. Set aside.
In a large bowl, whisk together the cooled butter (it’s ok if it’s a little warm, but it can't be hot), brown sugar, and white sugar.
1/2 cup butter, 2/3 cups light brown sugar, 2 tbsp white sugar
Add in the egg and vanilla and whisk until the mixture is light in colour and smooth in consistency.
1 egg, 1 tbsp vanilla
Toss in the flour, baking soda, and salt (if using) and gently fold in until almost combined. Add in the toffee bits and chopped up pistachios continue to fold until there are no flour streaks showing. (If the dough is very soft and hard to scoop, chill for 15 minutes).
1 1/4 cup all-purpose flour, 1/2 tsp baking soda, 1/2 tsp salt, 1/2 cup toffee pieces, 1/2 cup roasted and salted pistachios
Use a cookie scoop to scoop cookie dough balls onto the lined baking sheet, and bake 5-6 cookies at a time.
Bake for 12-15 minutes. You’ll know it’s ready when the edges are golden brown but the center looks puffy and slightly underdone.
When the cookies are fresh from the oven, sprinkle with a dash of flakey sea salt and add extra chopped pistachios and chocolate if desired.Allow the cookies to cool on a cooling rack, and enjoy!
flakey sea salt