Line two large baking sheets with parchment paper or silicone baking mats and set aside.
Whisk together the flour, Dutch processed cocoa powder, salt, and baking powder in a medium size bowl. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment or a medium size bowl with a handheld electric mixer, cream together the butter and both sugars on medium high speed until light and fluffy, about 2-3 minutes. Add the egg yolk and the vanilla then beat again until completely combined. Scrape down the sides of the bowl as necessary.
Turn the mixer speed to low, then slowly add the dry ingredients, mixing until just combined.
Using a 1.5 tablespoon cookie scoop, drop mounds of cookie dough onto the prepared baking sheets until you have used up all of the dough.
Using a ¼ teaspoon measure, gently press down on the tops of the dough balls to create an indent. If the spoon is sticking to the dough, dip it into some cocoa powder. Once all of the cookie dough balls have been indented, chill in the refrigerator for at least 1 hour and up to 3 days. If you are chilling them for longer than 1 hour, cover them so the dough doesn't dry out. You can also chill them on a large plate or platter if you don't have enough room in the refrigerator for 2 large baking sheets. You can then transfer them from the plate or platter to the prepared baking sheets.
When you are ready to bake the cookies, preheat the oven to 350ºF (177ºC). Bake the cookies no more than 8 to a baking sheet for 9 to 11 minutes (10 minutes worked best for me and my oven) until the edges are set.
Remove the cookies from the oven, then press down gently again with the ¼ teaspoon measure to re-shape the wells while the cookies are still hot. Allow the cookies to cool for at least 5 minutes on the baking sheet before transferring to a cooling rack to cool completely before filling with caramel.
CARAMEL FILLING
In a small bowl with a spout (preferably a glass measuring cup with a spout), combine the unwrapped caramels, 2 teaspoons of milk, and salt. Melt in the microwave on HIGH for 30 seconds, stir, then continue to microwave in 15 second intervals, stirring after each, until you have a smooth, pourable mixture. Add an additional ½ teaspoon of milk if you need to thin it out more.
While the caramel is still very warm, slowly and carefully fill each chocolate cookie, taking care not to overfill the wells. The caramel will spread to the edges, so only fill it about halfway before adding more to fill to the brim. Allow the caramel to set before drizzling with chocolate.
CHOCOLATE DRIZZLE
When the caramel has set, melt the chocolate in a small bowl, then transfer to a piping bag fitted with a small round tip, a cookie decorating bottle, or a zip top bag with the corner snipped off to drizzle chocolate over the top. You could also do more of a haphazard drizzle just using a spoon.
Allow chocolate to harden before serving. Do not stack cookies, but store in an airtight container at room temperature. If you need to stack them, place a piece of wax or parchment paper between layers. Un-filled cookies freeze well, up to 3 months. Do not freeze filled cookies. Allow to thaw at room temperature then fill.
Notes
Dutch processed cocoa powder: Rodelle is my preferred brand of Dutch processed cocoa powder. You can use any brand you like, just make sure it’s Dutch processed.
Caramels: I used Werther’s brand chewy caramels. You can use soft or chewy caramels, just don’t use hard candies or caramel sauce. You’ll want about 18 caramels total.
Nutritional information: all nutritional values are approximate.
