Preheat your oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper, leaving an overhang on two sides.

In a medium bowl, whisk together the melted unsalted butter, unsweetened cocoa powder, and hot water or brewed coffee until smooth.

In a separate large bowl, whisk together the eggs, granulated sugar, and vanilla extract until light and fluffy.

Carefully add the bloomed cocoa mixture into the egg mixture and mix until just combined.

In a small bowl, whisk together the all-purpose flour, whey protein powder, baking powder, and salt until there are no lumps.

Add the dry ingredients to the wet ingredients in 2 to 3 additions, mixing on low speed or by hand until just combined.

Gently fold in the chocolate chips until evenly distributed.

Pour the brownie batter into the prepared baking pan and spread evenly. Bake for 20 to 25 minutes until a toothpick comes out with moist crumbs.

Let the brownies cool completely in the pan on a wire rack before lifting out and cutting into squares.