Double Chocolate Peanut Butter Kiss Cookies

Preheat oven to 375 degrees F. Line baking sheet with parchment paper.
In a large bowl, cream together butter, peanut butter, sugar, and brown sugar until smooth.
Add egg, milk, and vanilla. Mix until well blended.
Gradually mix in flour, salt, and baking soda. Mix only until combined.
Roll dough into 1-inch balls. Roll dough balls into granulated sugar and place two inches apart on the baking sheet.
Bake until the cookies are very light brown and puffy, 6-8 minutes.
Remove the baking sheet from the oven and lightly press a Hershey's Kiss into the center of each cookie, allowing it to crack slightly.
Return to the oven 2-3 minutes until the cookies are light golden brown.
Remove from oven and press a second Hershey's Kiss on the top of the first one, allowing the melted kiss to squish down.
Cool 5 minutes on the baking sheet then remove to a sheet of waxed paper to cool completely.