Preheat the oven to 180˚C.
Mix Dr. Oetker Nona Tarts Original with butter and egg until completely incorporated. Add chocolate chips, and mix together until evenly distributed.
Form the cookie shots inside the paper cups, making the walls of the cookie shot about 5mm thick, and 5cm tall.
Bake for 20 minutes or until the cookies just start to brown. Remove from the oven, and let cool completely before removing cookies from paper cups.
Melt Dr. Oetker Nona Cooking Chocolate, and then pour the melted chocolate into the well of each cookie. Let it sit for a minute, and then pour the excess chocolate back into the pan. Chill cookie shots until the chocolate has set.
Pour milk into cookie shot before serving.