**Preheat Oven**: Set your oven to 350°F.

**Melt Butter**: In a microwave-safe bowl, melt the butter for about 30 seconds in the microwave.

**Mix Sugars**: Add brown sugar and sugar to the melted butter. Stir until the sugars dissolve and the mixture is smooth.

**Add Wet Ingredients**: Stir in the egg yolk and vanilla until well combined.

**Combine Dry Ingredients**: Fold in the flour and baking soda, then stir in the chocolate chips.

**Form Cookies**: Drop the cookie dough onto a parchment-lined baking sheet. This recipe makes 2 to 3 cookies, depending on size. Use a light-colored baking sheet for best results.

**Bake**: Bake for 8-10 minutes. Don't overbake; the cookies will continue to cook on the warm baking sheet after you remove them from the oven.