Preheat your oven to 180°C (350°F) and line a baking tray with parchment paper so the cookies don’t stick and cleanup stays easy. If you don’t have parchment paper, lightly grease the tray with a small amount of oil or butter.
In a mixing bowl, add the peanut butter, egg, and vanilla extract. Mix them together until the mixture becomes smooth, creamy, and fully combined with no streaks of egg visible. Take your time here—this step creates the base texture of your cookies.
Add the protein powder, sweetener, baking soda, and salt into the same bowl. Stir gently until everything is evenly incorporated and a thick dough forms. If the dough feels too dry or crumbly, add 1–2 tablespoons of milk to loosen it slightly. Avoid overmixing, as this can make the cookies dense.
Fold in the chocolate chips using a spatula or spoon, making sure they are evenly distributed throughout the dough so every cookie gets a good amount of chocolate in each bite.
Scoop small portions of dough (about 1–2 tablespoons each) and place them onto the prepared baking tray, leaving some space between each one as they will spread slightly while baking.
Gently flatten each dough ball using the back of a spoon or your fingers to form cookie shapes. You can press lightly—don’t flatten them too much, as they should stay slightly thick for a soft center.
Place the tray in the preheated oven and bake for 10–12 minutes. Keep an eye on them—the edges should look set and lightly golden, while the centers should still appear slightly soft. This is key to achieving a chewy texture.
Remove the cookies from the oven and let them sit on the tray for about 5 minutes, then transfer them to a cooling rack or leave them on the tray for another 5–10 minutes. They will firm up as they cool, so don’t worry if they seem soft at first.
Serve the cookies warm for a gooey, melty chocolate experience, or let them cool completely if you prefer a firmer texture. Store any leftovers in an airtight container to keep them fresh for later.