Mix together the flour, salt and baking powder in a bowl. In a separate bowl, cream the butter and sugar with an electric mixer until it becomes light and fluffy. Add the milk, egg and vanilla and mix well. Slowly add the flour mixture until it is just combined.
Shape the dough into a ball, then divide it into two balls. Wrap them in plastic wrap and place in the refrigerator for 1 hour. Lightly dust some flour onto your countertop, and roll the dough out until it is 1/4-inch thick. Find a cookie cutter that is just slightly larger than the base of a Hershey's chocolate kiss. (Water bottle caps work great!) Cut out circles and place on a baking sheet lined with parchment paper. Use a fork to create a check pattern on top. Bake at 350°F for 10-15 minutes, until golden brown. Cool completely.
Assembly: Place the peanut butter in a piping bag and pipe a dollop of peanut butter between 2 cookies and press them together. Place a dollop of melted dark chocolate on the center of each cookie sandwich and attach a chocolate chip. Place more melted chocolate onto the base of the Hershey's kisses and attach to the other side of the cookie sandwiches.
Place in the fridge for 20 minutes for the chocolate to harden, then enjoy!