Adapted from: Ad Hoc

Preheat the oven to 350 F.  Butter and flour the bottom of a 9 X 9 inch glass or metal baking pan and set aside.

Sift together the flour, cocoa powder, and salt and set aside.

Melt half the butter in a small saucepan over medium heat, stirring occasionally so that it won’t burn. Put the remaining butter in a heat-resistant bowl. Pour the melted butter over the bowl of butter and stir to melt. After a minute or so, the butter should have a creamy appearance and should be close to room temperature. Don’t worry if there are bits of unmelted butter.

In the bowl of a stand mixer fitted with the paddle, mix together the eggs and sugar on medium speed for 3-4 minutes or until it’s thick and very pale. Mix in the vanilla. Then, on low speed rotate adding in 1/3 of the dry ingredients and 1/3 of  butter. Continue until both have been incorporated. Don’t overmix here–just combine. Add in the chopped chocolate and quickly mix to combine (This batter can be refrigerated for up to 1 week).

Spread the batter evenly in the pan. Bake for 35-40 minutes or until a cake tester comes out clean. If it comes out wet and chocolaty, you may have hit a chip so try again. You don’t want to overbake these brownies. Cool until the brownies are at room temperature, run a knife around the edges of the pan, and invert onto a cutting board. But into 9 large 3″ brownies or 12 smaller brownies. They can be stored in an airtight container for up to 2 days although they’re best eaten the same day.