Preheat your oven to 325°F. Line a 9x13-inch baking pan with parchment paper and coat with nonstick spray.
In a large mixing bowl, combine the softened butter with both the powdered and granulated sugars, along with the vanilla extract. Beat using a hand mixer on medium speed until thoroughly blended.
Add the flour incrementally, continuing to beat until fully integrated; the mixture will be crumbly yet cohesive when pressed.
Firmly press about three to four cups of the dough into the bottom of the prepared pan, creating an even base layer.
Place in the oven and bake for approximately 25 minutes, or until the crust is set and the edges are lightly golden. Allow to cool.
Meanwhile, place the caramel bits and heavy cream in a saucepan over medium heat. Stir continuously until melted and smooth. Spread the caramel evenly over the cooled shortbread base using an offset spatula.
Distribute the chocolate chips uniformly over the caramel layer.
From the remaining dough, use a small cookie scoop to portion balls. Flatten each ball into a disc and place them over the chocolate chips, slightly overlapping if necessary.
Return to the oven and bake for 35–40 minutes, until the topping is golden brown. Let the bars cool completely at room temperature.
Once cooled, slice into bars and serve.