Preheat oven to 350°F (180°C). Line baking sheets with parchment paper.
In the bowl of a stand mixer fitted with the paddle attachment, beat peanut butter, sugar, oats, egg, baking soda, vanilla, and salt at medium speed until combined. Add peanuts and chocolate morsels, stirring gently with a spatula or a wooden spoon. Using a small (2-teaspoon) spring-loaded scoop, scoop dough, and shape into balls. Place dough 2 inches apart on prepared pans.
Bake for about 13 minutes. Let cool completely. Pipe Peanut Butter Cream Cheese Filling onto flat side of half of cookies. Place remaining cookies, flat side down, on top of filling. Refrigerate until ready to serve. Let stand at room temperature for 30 minutes before serving. Refrigerate in an airtight container for up to 1 week.
Recipe by Bake from Scratch at https://staging.bakefromscratch.com/flourless-peanut-butter-cookies-with-peanut-butter-cream-cheese-filling/