1. 1. Prepare your baking pan: Preheat your oven to 350 F (175 C). Lightly grease an 8×8 inch square baking pan and line it with parchment paper, leaving an overhang on two sides. This makes it much easier to lift the brownies out once they’re baked and cooled.

2. 2. Melt the butter and combine with sugar: In a large mixing bowl, pour the melted butter. Add the granulated sugar and whisk them together until well combined and smooth. This creates the base for your fudgy brownies.

3. 3. Add wet ingredients: Crack the eggs into the butter-sugar mixture, one at a time, whisking well after each addition until fully incorporated. Stir in the vanilla extract. The mixture should become light in color and slightly fluffy.

4. 4. Combine dry ingredients: In a separate medium bowl, whisk together the all-purpose flour, unsweetened cocoa powder, dark chocolate protein powder, baking powder, and salt. Make sure there are no lumps in the cocoa or protein powder.

5. 5. Mix wet and dry ingredients: Gradually add the dry ingredient mixture to the wet mixture, stirring with a spatula or wooden spoon until just combined. Be careful not to overmix the batter; overmixing can lead to tougher brownies. A few streaks of flour are okay.

6. 6. Fold in chocolate chips: Gently fold in the dark chocolate chips or chunks. Spread the batter evenly into your prepared 8×8 inch baking pan.

7. 7. Bake to perfection: Bake for 25-30 minutes, or until a toothpick inserted into the center comes out with moist crumbs, but not wet batter. The edges should look set, but the center might still be slightly soft, which is perfect for fudgy brownies.

8. 8. Cool before cutting: Let the brownies cool completely in the pan on a wire rack before lifting them out using the parchment paper overhang. This allows them to set properly and makes for cleaner cuts.