Pre heat the oven at 325 degrees, then melt that butter! Use a cast iron pan on low heat. You want it just melted, not hot. This is crucial - hot butter will give you sad cookies that spread too much. Hot butter can also cook the eggs in the mixing bowl

While the butter's cooling a bit, mix your brown and white sugars in a large bowl.

Once the butter's just warm (not hot!), mix it into your sugars until well combined.

Add your egg, extra yolk, and that splash of vanilla. Mix just until they're happy together.

Then add your flour, salt, and baking soda.

Here's where people often go wrong - when combining wet and dry ingredients, mix JUST until they're combined. Overmixing is the enemy of chewy cookies! Use your stand mixer, hand mixer, or whisk, but stop as soon as the flour disappears.

Fold in those chocolate chips - gentle does it!

Using your medium cookie scoop (my favorite tool for consistent cookies), drop dough onto those ungreased insulated cookie sheets. Give them some space - about 2 inches apart.

Now the magic number: 17 minutes, or until the edges just start to brown. Here's the trick - take them out before they look done! They should NOT feel firm. They'll keep baking as they cool.

Yes, they'll stick to the pan at first - that's normal! Let them cool a bit, then slide them off with your metal scraper.