Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat to prevent sticking and ensure even baking.

In a large mixing bowl, combine the peanut butter, honey or maple syrup, egg, and vanilla extract. Stir until smooth and fully blended. The mixture should be thick but glossy.

Add the protein powder, oats or oat flour, baking soda, and salt to the bowl. Mix gently until a thick cookie dough forms. Avoid overmixing, as this can lead to dry cookies.

If using chocolate chips, chopped peanuts, or spices, gently fold them into the dough using a spatula.

Use a cookie scoop or spoon to portion dough onto the prepared baking sheet. Space cookies about 2 inches apart. Slightly flatten each cookie with the back of a spoon or fork, as protein cookies do not spread much during baking.

Bake for 10–12 minutes, or until the edges are set and the centers are slightly soft. Do not overbake—protein cookies firm up as they cool.

Remove from the oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a cooling rack. Let them cool completely to achieve the best texture.