Step 1: Preheat your oven to 350°F (175°C) and line a 9x9 inch baking pan with parchment paper.
Step 2: In a large bowl, cream together 1 cup of softened butter and 1/2 cup of granulated sugar until smooth.
Step 3: Gradually add the flour to the butter mixture, mixing until a soft dough forms. Press the dough evenly into the bottom of the prepared pan.
Step 4: Bake the shortbread for 20 minutes or until the edges are lightly golden. Remove from oven and let cool completely.
Step 5: In a medium saucepan, combine 1/2 cup butter, brown sugar, condensed milk, and salt. Bring to a boil over medium heat.
Step 6: Boil for 5 minutes while stirring constantly until the mixture thickens and turns a light amber color. Pour over the cooled shortbread.
Step 7: Refrigerate the bars for 1-2 hours until the caramel layer is firm.
Step 8: Melt the chocolate chips and coconut oil together in the microwave in 30-second increments, stirring until smooth. Pour over the caramel.
Step 9: Chill for another hour until the chocolate is set, then slice into bars and serve.