Preparation Steps

• Preheat oven to 350 degrees Fahrenheit (175°C). Grease a 9x13 inch baking pan.
• In a medium bowl, beat together the eggs, cocoa powder, baking powder, espresso powder, and vanilla extract until the mixture is smooth.
• Melt the unsalted butter in a small microwave-safe bowl.
• Add the granulated sugar to the melted butter and combine well. Microwave the mixture in 10-15 second increments, stirring after each, until the mixture is hot (about 110-120°F or 43-49°C) but not bubbling. It should develop a shiny appearance, which helps in dissolving the sugar for a crinkly crust. This step can also be done in a saucepan over low heat.
• Add the hot butter-sugar mixture to the egg mixture and mix until smooth and well combined.
• Microwave the chocolate chips in approximately 20-second increments until they are fairly soft but not completely melted.
• Add the all-purpose flour and the softened chocolate chips to the batter. Mix until just combined and smooth, being careful not to overmix.
• Pour the batter evenly into the prepared 9x13 inch pan. Bake for about 30 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs (indicating fudgy brownies).
• Once baked, remove the brownies from the oven and allow them to cool completely in the pan on a wire rack before slicing and serving.