Step 1

Preheat the oven to 350 degrees F. Lightly grease a large, rimmed baking sheet (12X18-inches) and set aside.

Step 2

In a large microwave-safe bowl, combine the butter and chocolate; microwave in 1-minute intervals, stirring in between, until the mixture is melted and smooth (don't overheat, it should be slightly warm, if at all). Add the sugar and stir until combined.

Step 3

Whisk in the eggs and vanilla, and mix until large bubbles pop at the surface - it will go from looking slightly curdled to really glossy and thick so keep stirring until you see the change. In a separate smaller bowl, whisk together the flour, baking powder, and salt. Add the dry ingredients to the batter and mix once or twice. With dry streaks remaining, add the chocolate chips and mix until well-combined.

Step 4

Spread the batter evenly in the prepared pan.

Step 5

Bake for 25-30 minutes until edges are set but the middle is still slightly gooey. If you want extra dense, fudgy brownies, halfway through the baking time, carefully lift up the baking pan and let it drop on the oven rack to release any air bubbles (totally optional). Let the brownies cool completely in the pan (I like to refrigerate them after they have baked and cooled - easier cutting and ultra-delicious, and don't get me started on how incredible these are straight from the freezer).