In a medium-sized mixing bowl, combine the melted butter, sugar, brown sugar, salt, and cocoa powder. Mix until combined, add the eggs and vanilla and whisk.
Add the flour to the butter and sugar mixture and fold in using a rubber spatula. Once it is almost completely mixed, add the chocolate chips and fold until combined.
Bake in a preheated oven for 30- 40 minutes, or until the edges of the brownies are crisp and a toothpick inserted into the center comes out mostly clean.