In a medium bowl whisk together flour, cocoa powder, baking soda, and salt. In a large bowl beat together butter, brown sugar, and sugar until light and fluffy (2-3 minutes). Mix in egg and vanilla until blended.
Gradually mix in dry ingredients on low speed until just incorporated, don’t over mix. Stir in the chocolate chips by hand. (I reserve 1/4 cup for adding at the end) Cover TIGHTLY and chill for 2 hours or overnight.
Preheat oven to 350°F and take the dough out of the fridge while the oven is preheating.
Roll 2-3 tablespoons of cookie dough into a ball. Break the ball in half and place one half on a baking sheet. Press a Rolo into the center of the cookie dough, top with remaining half of the cookie dough ball and press down on top of the Rolo to cover it completely. Press a few chocolate chips into the top. Repeat with remaining dough and Rolos, placing cookies about 3 inches apart on a baking sheet.
Bake for 10-12 minutes until the tops of the cookies are just set. Sprinkle immediately with sea salt to taste, then allow to cool on the baking sheet for 5 minutes before transferring to a cooling rack to cool completely.
Serve at room temperature for chewy caramel OR for melty caramel, pop a cookie in the microwave for 8-10 seconds (this is for my microwave, you might need to test with yours to find how many seconds yields a melted caramel center). Store in airtight container.