Step 1: Preheat your oven to 350°F (175°C). Grease and flour a 9×13 inch baking dish. In a large mixing bowl, prepare the yellow cake mix according to the package instructions. Pour the prepared batter into the greased baking dish and spread it evenly.
Step 2: Bake your cake in the preheated oven for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean. Once baked, remove it from the oven and allow it to cool for about 10 minutes.
Step 3: While your cake is still warm, take a fork and poke holes all over the surface.
Step 4: Slowly pour the sweetened condensed milk over the warm cake, ensuring that it seeps into the holes you’ve made.
Step 5: Drizzle the caramel sauce over the top of the cake, spreading it evenly. Allow the cake to absorb the flavors as it cools completely, approximately 30 minutes more.
Step 6: Once the cake has cooled, take your Cool Whip and gently spread it over the top.
Step 7: Chop the Butterfinger candy bars into small pieces and sprinkle them generously over the top of the Cool Whip layer.
Step 8: Refrigerate the Butterfinger Cake for at least 2 hours before serving.
Notes
For an even richer flavor, use a chocolate cake mix instead of yellow. Don’t skip the chilling step; it helps the flavors to meld beautifully.