Place the butter in a light-colored saucepan over medium heat and let it melt completely. Stir continuously as it begins to foam. After a few minutes, you’ll notice small golden-brown bits forming at the bottom and a rich, nutty aroma developing—this is exactly what you want. As soon as the butter turns a deep golden color (not dark brown), remove it from the heat immediately to prevent burning. Pour it into a heat-safe bowl and allow it to cool completely to room temperature before using.

In a large mixing bowl, add the cooled brown butter along with the brown sugar, white sugar, and vanilla extract. Using a whisk or electric mixer, beat everything together until the mixture becomes smooth, creamy, and slightly thick. Take your time here—proper mixing helps dissolve the sugar and improves the final cookie texture.

Add the eggs one at a time, mixing well after each addition. Continue mixing until the mixture looks glossy, slightly fluffy, and fully combined. This step is key for achieving soft centers and a balanced structure.

In a separate bowl, combine the flour, protein powder, baking soda, and baking powder. Mix thoroughly so everything is evenly distributed and there are no lumps of protein powder or uneven leavening.

Gradually add the dry ingredients into the wet mixture in batches, mixing gently with a spatula or on low speed if using a mixer. Stop as soon as everything is combined and no dry streaks remain. Avoid overmixing, as this can make the cookies dense and tough.

Add milk one tablespoon at a time, gently mixing after each addition until the dough becomes soft, smooth, and scoopable. The dough should hold its shape but not feel dry or crumbly. Be careful not to add too much liquid, as that can cause the cookies to spread too much during baking.

Fold in the chocolate chunks using a spatula, making sure they are evenly distributed throughout the dough. Try not to overmix—just fold until combined so the dough stays tender.

Cover the dough and let it rest at room temperature for 20–30 minutes. This resting time allows the flour and protein powder to fully hydrate, resulting in a softer dough and better texture after baking.

Line a baking tray with parchment paper. Scoop portions of dough (about 60–70g each) and place them on the tray, leaving enough space between each one to allow for spreading.

Preheat your oven to 180°C (350°F). Place the tray in the center rack and bake for 10–12 minutes. The edges should look set and lightly golden, while the centers may still appear slightly soft—this is ideal for a chewy texture.

Remove the cookies from the oven and let them rest on the tray for a few minutes before transferring them to a cooling rack. This allows them to firm up slightly while keeping the inside soft and gooey. Serve warm for the best flavor and texture.