1. Preheat the oven to 350°F (175°C) and prepare an 8×8-inch or 9×9-inch baking pan by lining it with foil or parchment paper. Spray the lined pan with cooking spray to prevent sticking.
2. In a mixing bowl, combine melted butter, brown sugar, and vanilla extract. Stir in the flour, old-fashioned oats, and baking soda until a soft dough forms.
3. Divide the cookie dough in half. Press one half of the dough evenly into the prepared baking pan to form the base layer.
4. Bake the base layer in the preheated oven for 8-12 minutes, or until it turns lightly golden. Remove from the oven and set aside.
5. In a saucepan over medium-low heat, melt the caramel squares with heavy cream. Stir frequently until the mixture is smooth and consistent, creating a thick caramel sauce.
6. Once the base layer has baked, sprinkle an even layer of semi-sweet chocolate chips on top of it.
7. Pour the melted caramel sauce evenly over the chocolate layer, ensuring complete coverage.
8. Crumble the remaining cookie dough over the caramel layer to create the topping.
9. Return the pan to the oven and bake for an additional 15-20 minutes, or until the top layer is golden brown.
10. Remove the Carmelitas from the oven and cool completely at room temperature to allow the caramel to set properly before slicing.
11. For best results, refrigerate the Carmelitas for at least 1-2 hours before cutting them into neat bars.
12. Bring to room temperature before serving to enjoy the perfect blend of gooey caramel and chewy oatmeal layers.