Preheat your oven to 350 Degrees F. In the bowl of your stand mixer, cream together butter and sugar until light and fluffy. Add Vanilla and mix to combine.
In a separate bowl, combine flour, baking power, baking soda, and cocoa powder. Whisk to combine. Gradually add dry ingredients to butter mixture. Combine thoroughly.
Using a teaspoon, form cookie dough into balls, flattening slightly. Place on a cookie sheet lined with parchment paper. Bake for 8 minutes.
Remove cookies from oven and using a tsp measure, lightly press the rounded side into the warm cookies creating a divot in the center. Return to the oven and back for 3-4 more minutes. Remove and cool.
Once cookies have cooled, add dulce de leche filling with a teaspoon to the center of each cookie. Follow with sea salt. Serve immediately or refrigerate in an airtight container for up to 3 days.