Step 1

Preheat oven to 325°F. Line a 17x12-inch baking pan with parchment paper and lightly grease the sides. NOTE: if you use a half sheet pan which is 18x13-inches, then these brownies will be thinner. I suggest to make a 1-inch border along one width and one length of the half sheet pan using foil or parchment to ensure the batter is thick enough.

Step 2

Combine chocolate and butter in a saucepan over very low heat and stir constantly until melted and smooth, or melt in the microwave at 50% power in short 20-second bursts with frequent stirring. Set aside but keep it warm (it doesn’t need to cool).

Step 3

Combine eggs, sugar and salt in a large bowl and whisk vigorously until pale and thick. This will take a minute or two with a hand whisk. You can also use a hand mixer to get the job done faster. Add the warm melted chocolate mixture and mix it in or beat it in until evenly combined and smooth. The mixture will tighten up and look glossy once the chocolate is incorporated well.

Step 4

Combine flour and cocoa powder in a medium bowl and whisk to blend evenly. If your cocoa is lumpy, I recommend sifting it first. Sprinkle it over the surface of the chocolate batter and fold it in until evenly combined. Spread the batter evenly into the prepared pan and sprinkle chocolate chips on top.

Step 5

Bake for 25-30 minutes until the surface is shiny and cracked and it feels slightly firm in the center. A skewer inserted into the center will come out with a few sticky crumbs attached (not completely clean). It will puff up in the oven after the first 20 minutes and then sink a bit and then it will be ready shortly after.