Preheat the oven to 350°F (175°C).
In a medium bowl, mix together the flour, cocoa powder, baking soda, and salt.
In a large bowl, beat the softened butter, granulated sugar, and brown sugar until fluffy.
Add the egg and vanilla extract to the butter mixture, and mix until well combined.
Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Scoop tablespoon-sized portions of dough into a greased muffin tin, pressing them down to form cups.
Bake in the preheated oven for 12-15 minutes, or until the edges are set.
Allow the cookie cups to cool for 10 minutes before filling with caramel sauce.
Fill each cup with caramel sauce, then let it set while you melt the chocolate chips.
Melt the chocolate chips in a microwave-safe bowl, stirring until smooth.
Spoon the melted chocolate over the caramel-filled cookie cups.