Preheat the oven to 325ºF and line a large baking sheet with a silicone mat. Use two baking sheets if yours are small, as these cookies will spread.
In a large bowl, beat together the peanut butter and sweetener until well combined. Beat in the eggs and vanilla extract.
Add the protein powder, cocoa powder, baking powder, and salt and beat until well combined. Stir in about half of the peanut butter chips.
Roll the dough into 16 balls, each about 1 ½ inches in diameter, and place on the prepared baking sheet. Press down with the heel of your hand to about ½ inch thick.
Bake 10 to 12 minutes, until puffed and set around the edges. Do NOT over-bake them as they can dry out easily.
Remove and immediately press the remaining chips into the tops of the cookies. Let cool completely on the pan.
Notes
Storage Information: Store the cookies in a covered container on the counter for up to 4 days or in the fridge for up to a week. You can also freeze them for several months.