The Best Fudgy Brownies

Name: The Best Fudgy Brownies
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: American
Ingredients: 2 large eggs (room temperature); 1/2 cup unsalted butter (melted and cooled slightly); 1/2 cup granulated sugar; 1/2 cup brown sugar (packed); 2 teaspoons pure vanilla extract; 1/2 cup all-purpose flour; 1/2 cup unsweetened cocoa powder; 1/2 teaspoon espresso powder (optional, but encouraged); Pinch of kosher salt; 1 cup chocolate chips or chopped chocolate (divided (optional, but encouraged))