Prepare the caramel sauce. Set aside to cool.
Preheat the oven to 350°F(177°C). Grease regular size 12 cup nonstick cupcake/muffin pan and set aside.
Place the flour, baking soda and salt in a medium bowl, set aside.
Melt the butter halfway over medium heat in a small-medium pan. Remove from the heat and stir with a spoon so the butter cools fast.
Place the brown sugar, granulated sugar and melted butter in a large bowl and mix with a whisk until combined well.
Add the egg and stir for a couple of seconds until combined. Mix in the vanilla.
Add flour mixture in 2-3 batches until it is totally incorporated. You can use a whisk in your first batch but then use a spoon/spatula as it makes stirring easier.
Add the chocolate chips and stir with a spoon/spatula evenly.
Roll the dough into almost 2 and ½ tablespoon (54 grams) balls. Place them into the cupcake/muffin pan. Press the balls onto the bottom and up sides to give a cup shape with your fingers.
Bake for 12-14 minutes until they are golden brown. The dough will be puffy when they are out of the oven. Wait for 2 minutes and then using the back of a tablespoon, gently press the center and sides to give their cup shape again. Let the cookie cups cool in the pan for 10 minutes. Gently remove the cookie cups with a toothpick.
Fill each cookie cup with almost 1 tablespoon of caramel sauce. Sprinkle pinch of coarse sea salt on top. Keep them in the fridge until the caramel sets.