Preheat the oven to 400°F.
Line a baking sheet with parchment paper and set to the side.
In the bowl of your mixer beat together butter, vanilla extract, baking powder, and sugar.
Add the egg and beat until the mixture just starts to come together.
Slowly add the flour a ½ cup at a time alternating it with the milk.
Scoop about a tablespoon of cookie dough and drop it on the baking sheet. Repeat this step spacing the dough about 2 inches apart.
Lightly grease the bottom of a measuring cup and press it gently down on the dough balls, flattening them slightly so they are about 1 1/2 inches across. You will need to grease the measuring cup several times during the process so the dough doesn’t stick to it. I just used a little non-stick spray.
Bake the cookies for 8-10 minutes. This cookies are cake-like so you don’t want the bottoms getting fully brown. They are done when the bottom is a mottled brown.
Once cookies are done remove them from the oven and place them on a cooling rack.
Make the frosting by placing the two types of chocolate chips in a bowl.
In a separate, microwave safe bowl, add the heavy cream and microwave it for 30 seconds at a time until it begins to boil.
Pour the boiling milk over the chocolate chips and let it sit.
Add the light corn syrup to the chocolate and stir until it is smooth.
Stir in the powdered sugar and let them mixture sit for 5 minutes to cool slightly.
Take each cookie and turn it over, dipping the flat bottom in the chocolate icing.
Let the chocolate mixture continue to cool and then using a knife scoop up more chocolate and spread it over each cookie. If you can see swirls in the icing after you spread it over the cookie then it is the right consistency. In the end the chocolate should be about the same thickness as the cookie.
Let the chocolate set and then store in an airtight container until ready to serve.