Preheat your oven to 350F and line 2 pans with parchment paper.
In the food processor, process the oats into a flour-like meal. This might take a few minutes.
Do the same with the peanuts but make sure not to over-process or the peanuts will be too oily, just until you have evenly crushed peanuts.
In a bowl of a standing mixer, place the shortening, sugar, peanut butter, egg, and salt, and mix until you get a smooth mixture.
Add the oats and peanuts and mix to combine.
Using a cookie spoon, scoop the cookie dough on the pans, and using the back of a fork, mark each cookie from top to bottom and then from side to side.
Bake for 15-18 minutes or until the cookie is golden on the sides.
Notes
To make the cookies vegan, Consider adding a source of a stabilizer like xanthan gum in addition to a flax egg so the cookies will not crumble.
The cookies might crumble if you immediately move them to a wire wrack, allowing them to cool for 20 minutes.
All of the ingredients must be at room temperature.
You can use nut butter and nuts to replace the peanuts and PB. Other options are sunflower seeds and sun butter.
Regular peanut butter might be too sweet, so consider reducing up to 1/4 cup of sugar.