Preheat oven to 375 degrees. Line two cookie sheets with parchment paper.
Using an electric mixer, beat the butter, sugar, egg, salt and vanilla extract just until smooth and creamy.
Add the flour a little at a time and mix just until incorporated and dough like. Cover the dough and refrigerate for 30 minutes (this is important, make sure to do it).
Drop rounded tablespoons of the dough onto the prepared cookie sheets about 2 inches apart and use a spoon to press each down into neat circles. Use the top of the spoon to press a small well into the center of each cookie.
Drop 1 teaspoon of the Dark Chocolate Drams peanut butter into the well in each cookie.
Bake for 10-12 minutes, until edges of cookies turn golden brown. Let cool.