Start by browning your butter. In a saute pan, heat to medium. Add butter to pan and let melt down and crackle. Whisk continuously and often during the browning period. Browning takes about 5-7 minutes. Once it is amber brown like maple syrup, turn off heat. Pour brown butter into dish and let cool for an hour.
In a large bowl, add cooled brown butter. Using a hand mixer, beat both brown and white sugar into butters until creamy. Add eggs and vanilla and mix again until combined.
In a medium bowl, stir together flour, baking soda, baking powder, and salt.
Add dry ingredients to wet ingredients and stir until all combined.
Chop chocolate bars into small chunks and mix into dough, along with the chocolate chips. I like to save a few chunks of chopped bar for topping the cookies.
Let dough chill at least 4 hours or overnight (preferred). When ready to bake, let rest 30 minutes before trying to scoop if refrigerated overnight.
Roll about 2tbsp dough into balls and place on parchment lined baking sheet.
Bake for 12-14 minutes at 350F or until very lightly golden brown around edges. Sprinkle with flakey sea salt.
Let cool on sheet for 10 minutes and then move to cooling rack to finish cooling.