Melt butter in a medium sauce pan over medium-high heat. Continue to heat as butter starts to bubble - the bubbling sounds will get louder as the butter heats up. Stir constantly, scraping the bottom and sides of the pan with a spatula as you go. Keep a close eye on it as it will change color quickly. Once the butter turns a nice dark golden brown and has a nutty aroma, remove it from the heat. Transfer butter to a heat-proof bowl and let cool. You may place it in the fridge for 15-20 minutes to speed up the process.

Preheat the oven to 375 degrees F.

Combine flour and baking soda in a medium bowl and set aside.

Once butter is cooled, but not hardened, place in the bowl of a stand mixer, along with both sugars, salt, and vanilla. Using the paddle attachment, mix until light and fluffy, about 3-5 minutes.

Add egg and egg yolk and mix until combined.

Mix in flour mixture until just combined.

Stir in chocolate chips and Heath chips with a spoon or spatula.

Scoop 2 Tbs of dough at a time onto a baking sheet lined with parchment paper. You'll need to do at least two separate batches in the oven. Should make about 24 cookies.

Bake for 9-12 minutes, till the edges just start to brown. Remove from oven, sprinkle with additional salt, and let cool a few minutes before removing from the pan.