In a light-colored saucepan, melt the butter over medium heat. Stir constantly. After it foams and crackles, brown bits will start forming at the bottom and it’ll smell nutty. Stay around because the butter will start browning fast. Once golden brown (not burned), remove from heat and pour into a mixing bowl. Cool for about 30 minutes.

Add brown sugar and granulated sugar to the browned butter. Beat with a mixer. You can use a hand mixer or a stand mixer with the paddle attachment.

Once the sugar and butter are incorporated, add the eggs one at a time, beating until completely incorporated before adding the next one. Then add the vanilla. Beat until the mixture looks smooth

Add the flour, baking soda, baking powder, and salt to the bowl. Mix just until combined.

Fold in toffee bits and nuts, if using.

If you don’t want to freeze them, simply scoop the cookies and keep them in the fridge (covered) for at least another hour before baking, ideally overnight. The longer the chill, the richer the flavor and also better the texture and structure of the cookies.

You can bake some right away, but they might spread without the proper chilling time.

Bake for 10–12 minutes, or until edges are golden and centers still look slightly underbaked. They’ll finish setting on the tray.

You can sprinkle a touch of sea salt, such as Maldon, once the cookies come out of the oven.

Let them cool on the tray for 5 minutes, then transfer to a rack.