Preheat oven to 325F. Grease or parchment-line a 9x13-inch metal pan. Set aside.
In a large saucepan, combine butter, sugars, and water.
Bring to a boil, stirring regularly.
Remove pan from heat.
Whisk in 1 3/4 cups chocolate chips until melted and well-combined.
Add eggs and vanilla.
Whisk until well-combined.
Add flour, salt, and baking soda.
Whisk in just until combined. Don't overmix.
Stir in the remaining 3/4 cup chocolate chips
Pour the batter into the prepared pan, smoothing as needed.
Bake for about 35-45 minutes, or until a toothpick inserted in the center comes out with a few fudgy crumbs.
Let the brownies cool to room temperature before cutting and serving.
Butter: I use salted butter in this recipe. If using unsalted butter, increase the salt to 3/4 teaspoon.
Brown sugar: I use light brown sugar in this recipe.
Chocolate chips: Bittersweet chocolate chips are 60% cacao. A good substitute would be dark chocolate chips. If you prefer, you can use semisweet chocolate chips. However, the brownies will be sweeter.
If you like more chocolate chips in your brownies, feel free to increase the stirred in chocolate chips to 1 cup.
If you omit the stirred in portion of the chocolate chips, the brownies won't have as much of a shiny exterior.
All-purpose flour: It's important to use a light hand when measuring flour for brownies. To get the proper amount of flour, weigh the flour or sift or stir the flour. Lightly spoon into the measuring cup and level.
The brownies are good at room temperature but are even better after chilling in the fridge overnight.