Preheat oven to 325℉. Line a 9x13" pan with parchment paper.

Place butter, sugar, and 1 cup chocolate chips in a large glass mixing bowl. Microwave for 1 minute, stir, and microwave for 1 minute more. Whisk mixture until smooth. If chocolate or butter is not completely melted, microwave again in 30 second intervals until everything is melted and smooth. Once melted, whisk for about 1 minute. You'll still see sugar granules and that's okay!

Add eggs one at a time to chocolate mixture, mixing each time. Stir in vanilla and salt.

Tip: It's time to add the dry ingredients. I like to place a mesh sieve on top of my bowl and shake all my dry ingredients through it. Add flour, cocoa powder, and baking powder to bowl, preferably over a fine mesh sieve to avoid clumps. If you skip the sieve, mix dry ingredients in another bowl first and whisk to combine before adding to your brownie batter. Gently stir flour mixture into the batter until just mixed and no visible traces of flour remain. If you'd like chocolate chunks, stir in an extra cup of chocolate chips at this point. Do not beat or overmix!

Transfer pan to oven and bake for 30-35 minutes. Chocolate can be difficult to guage because of the color! Some visual cues to look for: Edges should be set and start to pull away from side of pan. You should see a crack around the perimeter of the brownies. The top should be papery and crackly. A skewer inserted in the center should come out without wet batter attached. Cool completely if frosting.

Melt ½ cup butter in a heat-safe bowl large enough to make icing in. Once Completely melted add ½ cup cocoa powder and ¼ teaspoon salt. Whisk until smooth, for about 30 seconds. This process blooms your cocoa powder for a more intense chocolate flavor.

Sift powdered sugar into the mixture and then beat with a hand mixer. Slowy add cream a little at a time until desired consistency is reached.