Preheat oven to 300°F. Coat a 9" x 13" baking pan with nonstick cooking spray. Set aside. In a large bowl, beat butter until creamy then add salt, vanilla and sugar. Beat until smooth. Slowly add flour and blend until well incorporated. Press flour mixture evenly into bottom of prepared baking pan. Bake 25–30 minutes or until edges begin to brown. Remove from oven and set aside to cool completely. In a medium microwave safe bowl, add caramel squares and cream then microwave on high 3 minutes or until caramel is just melted, stirring after each minute. Do not overcook. Spread the melted caramel over cooled crust and place in refrigerator for approximately 20 minutes to cool. In a double boiler over medium-high heat, melt chocolate chips 2–3 minutes or until smooth, stirring often. Spread evenly over cooled caramel and return to refrigerator until chocolate is set. Cut into squares and serve.