Preheat oven to 350°F (177°C). Line a large baking sheet with parchment paper.
Add peanut butter and egg to a large mixing bowl. Mix until egg is fully incorporated, no egg white streaks remain and the mixture forms a thick dough.
Use a 1.5 tbsp cookie scoop to scoop out dough and place onto the prepared baking sheet. Use the back of a fork to make criss-cross pattern onto the surface of each dough ball. Each cookie should be a thick round disk after making the criss-cross pattern. If it's not, you can use your fingers to shape the edges as needed. Place cookies into the oven and bake for about 12 minutes.
Let cookies cool on cookie sheet. Do not attempt to remove them before they are cooled because they will break. Once cookies are cooled you should be able to remove them from baking sheet. Cookies do break easily so be gentle when transferring them.
Notes
These cookies are not sweet. They are savory peanut butter cookies. They have a texture similar to biscuit cookies though they are more crumbly because they are made of so few ingredients. See post for more details on taste and texture.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.