Beat the softened butter on medium to high speed for 30 seconds.

Add the sugar and salt, then beat until combined.

Mix in the flour on low speed until fully incorporated, scraping down the sides of the pan as needed.

Press ⅔ of the mixture into the bottom of an un-greased 9x13 baking dish to create the shortbread layer.

Add the unwrapped caramels and sweetened condensed milk to a microwave-safe bowl and heat in the microwave on HIGH for 2 ½ minutes or until melted, stirring every 30 seconds.

Stir in the walnuts and vanilla extract then pour caramel mixture in an even layer over the layer of shortbread. Sprinkle small pieces of the remaining shortbread dough evenly over the caramel layer.

Bake the bars at 350 degrees for 25-30 minutes until the top begins to turn golden brown.

Remove from the oven and allow the bars to cool completely on a wire rack before cutting into 24 perfect bars.