Preheat the oven to 350F (177C) convection OR 325F (163C) conventional and line two cookie sheets with parchment paper.
In a medium bowl, microwave the butter for 20-30 seconds, just until it's melted (if it gets super hot, then let it cool a little bit).
1/2 cup (113g) salted butter
Add the light brown sugar to the melted butter and whisk together for about a minute.
3/4 cup (150g) light brown sugar
Add in the egg yolks and vanilla and whisk aggressively for 1-2 minutes, until it's completely smooth.
2 large egg yolks, 1 tsp vanilla extract
Add the flour, salt and baking powder and fold the cookie dough just until there are a few streaks left of flour.
1 cup (125g) all-purpose flour, 1/4 tsp fine sea salt, 1 tsp baking powder
Fold in the chocolate, just until they're evenly dispersed.
2/3 cup (4oz) chocolate chips or chopped chocolate
Split cookie dough into 8 small cookies, about 2.25 oz each, and bake one sheet on the middle rack for 11-13 minutes on convection or 13-15 minutes on conventional, just until the edges are starting to brown and the center is puffed and no longer wet.
Remove them from the oven, give the pan a quick tap on the counter and use something round like a biscuit cutter or cup to scoot them around so they're circular.
Allow them to rest for 5-10 minutes before transferring off the cookie sheet. Sprinkle with sea salt flakes and enjoy warm!
pinch sea salt flakes