Preheat oven to 350ºF, and lightly grease an 8-inch square pan with non-stick cooking spray. Line with parchment paper leaving extra overhang on the sides for easy removal.
In a separate bowl combine the flour, oats, baking soda and salt; set aside.
In a stand mixer fitted with the paddle attachment, beat the butter and brown sugar together until smooth and lightened. Add the egg and vanilla, mixing until combined. Add the dry ingredients, mixing until just combined.
Spread half of the dough into the bottom of the prepared pan. Using a spatula or the back of a spoon, smooth it out into an even layer; set remaining dough aside. Bake for 10 minutes.
While the bottom layer bakes, make the caramel sauce. Place the caramels and heavy cream into a medium saucepan set over medium-high heat. Stirring constantly, cook mixture until melted and completely smooth.
After 10 minutes, remove the pan from the oven and sprinkle the chocolate chips evenly on top. Drizzle the caramel sauce evenly over the chocolate.
Take the remaining dough, and evenly crumble it over the top.
Return the pan to the oven and bake for about 13-15 minutes, or until the edges are lightly browned.
Let bars cool completely in the pan before slicing and serving to allow the caramel to firm up. This can take around 4 hours, or overnight, at room temperature. You can speed up the cooling process by placing them in the refrigerator. If not allowed to cool completely, you'll end up with a sticky caramel mess. Not that that's necessarily a bad thing...