Preheat oven to 325 degrees and lightly grease and 8” square baking pan; set aside. In a large bowl, whisk whole egg and yolk until blended. Whisk in melted butter until mixture is slightly thickened. Stir in snickerdoodle mix until mixture is well-blended; set aside.
To make the caramel sauce, combine brown sugar, butter and cream in a saucepan over medium heat. Bring mixture to a boil, reduce heat to medium low and simmer for 2-3 minutes until thickened. Remove from heat and whisk in vanilla and salt. Allow mixture to cool 5 minutes.
Divide snickerdoodle dough in half and press into the bottom of the prepared pan. Drizzle half of the caramel mixture over the top, then crumble remaining snickerdoodle dough over caramel.
Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean and the caramel is bubbling. Cool to room temperature on a wire rack, then cut into 16 squares. Enjoy!