In a large bowl, using a hand mixer, combine the peanut butter, powdered sugar, vanilla extract and egg. Beat until smooth.
Remove about a 2 tablespoon portion of cookie dough mixture and place on a silicone mat-lined sheet pan. Cookies should be spaced about 2" apart.
Bake cookies at 350 degrees for 10-12 minutes, until tops and edges of cookies start to brown. Allow cookies to cool for 5-10 minutes on the baking sheet before gently moving to a wire cooling rack.
Notes
Leftovers can be stored at room temperature and should be enjoyed within 4-5 days of baking cookies.
This is the perfect cookie to freeze! Place in a freezer bag (with as much air as possible removed) and store in the freezer for up to 6 months after baking. When you're ready to serve them, just thaw and enjoy.
When cookies are removed from the oven, it might look like they haven't formed well. Let them cool for 5-10 minutes on the baking sheet; they should become firm while cooling.
This recipe yields only about 8 cookies. If needed, you can easily double or even triple the recipe.