Preheat oven to 350 degrees F. Spray a mini muffin tin with nonstick cooking spray; set aside.
In a large mixing bowl or stand mixer, combine Kodiak Cakes, Truvia and protein powder.
Mix in milk, peanut butter, salt, eggs and vanilla until well combined.
Roll dough into 1-inch balls and place in muffin tin.
Bake for 9-11 minutes, or until set.
Remove from oven and press a peanut butter cup into the center of each cookie. Let cool before removing cookies from muffin tin.