Line a cookie sheet with parchment paper and set it aside.
In a large mixing bowl, mix milk and peanut together. You can also use an electric mixer on low speed if you prefer.
Add the biscuit mix and the teaspoon vanilla, and fold together until everything is well combined and peanut butter cookie dough has formed.
Place about a cup of white sugar in a small bowl.
Then, using a cookie scoop, shape dough balls and roll each ball in sugar. Then place them about 2 inches apart on the ungreased cookie sheet.
Bake for about 10 minutes until the edges of the cookies are golden brown. Note: the bottoms of cookies may be darker.
Place a peanut butter heart candy into the center of each cookie and cool for 2 minutes on the pan. If your cookies crack when you press the chocolate down, that's ok. It's supposed to do that!
Transfer hot cookies to a wire rack to continue cooling and enjoy!
Notes
Store leftovers in an airtight container at room temperature for 3-5 days.