Preheat oven to 350 degrees and line baking sheets with parchment paper.
In a small bowl, mix together butter, eggs, and vanilla extract. Using hand beaters, mix well. If your butter is a little colder, it will be chunky and that is fine!
In a large bowl, mix together almond flour, oat fiber, sweetener and salt.
Add egg mixture to dry ingredients and continue blending with a hand blender. Using your clean hands, give it one final mix and just squish it between your fingers a little. This helps mix in the colder butter a bit more.
Cover dough and cool in the refrigerator for 10-60 minutes (less time is needed if your butter was colder).
Roll into small (1 inch) balls and then roll in the optional topping.
Press cookies down a bit so they are flatter. If you are topping with peanut butter cup chunks, you can press them into the top at this point.
Bake for 12 minutes and let cool before moving off the baking sheet.
Video
Notes
Nutritional is calculated without option toppings.