Preheat oven to 325℉. Whisk together flour, baking soda, and salt into a bowl and set aside
In a separate large bowl with an electric mixer beat together peanut butter, butter and sugars on medium-high speed until light and fluffy.
Add the egg, milk, and vanilla.
Beat on med-high until well incorporated
Add the flour mixture.
Mix on low just until the flour mixture is incorporated.
Shape the dough into 1-inch balls and place into lightly greased mini muffin cups. Bake 11-13 minutes or until lightly browned.
Remove from oven and immediately make wells by pressing a teaspoon into the center of each.
Cool in the tin for 5 minutes, then transfer to a cooling rack
Combine the chocolate chips and peanut butter in a microwave-safe bowl. Microwave in 30 second intervals, stirring between each round, until smooth.
Using a pastry bag or a small pitcher, fill each shell with filling.
Garnish with peanuts before filling sets.
Allow to cool about 2 hours for filling to set.