Step 1: Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
Step 2: In a large bowl, prepare the butter pecan cake mix according to package directions, using the specified amounts of eggs, oil, and water. Once the batter is smooth, stir in the entire can of coconut pecan frosting until well combined.
Step 3: Pour the batter into the prepared 9x13 inch baking pan. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
Step 4: Remove the cake from the oven and let it cool on a wire rack for about 10-15 minutes. While still warm, use the handle of a wooden spoon to poke holes evenly across the top of the cake, going about halfway through.
Step 5: In a medium bowl, whisk together the sweetened condensed milk and
half a cup of the caramel sauce until smooth. Slowly and evenly pour this mixture over the warm, poked cake, ensuring the liquid seeps into all the holes.
Step 6: Cover the cake loosely and refrigerate for at least 2 hours, or preferably overnight, to allow the cake to fully absorb the liquid and chill completely.
Step 7: Before serving, spread the thawed whipped topping evenly over the chilled cake. Drizzle the remaining
half cup of caramel sauce over the whipped topping, and then sprinkle the remaining
half cup of chopped pecans on top. Slice and serve cold.
Step 8: For extra richness, lightly toast the pecans in a dry skillet for 3-5 minutes before sprinkling them on the cake.