Begin by sifting the flour, sugar, and salt in a large stand mixer or bowl.
Add in the egg whites, cream of tartar, and vanilla, mixing well.
Pour the batter into a greased bundt pan or a greased 9x13 cake pan.
Place in a COLD oven and then set the temperature to 325°F and bake for 1 hour or until golden brown.
Let fully cool and then slice or tear the cake into bite-size pieces.
For the Butterfinger Cake:
Crush the candy bars in the food processor and set aside.
In a large mixing bowl, combine the butter, powdered sugar, Cool Whip, and vanilla. Mix and beat this well until a nice icing is formed.
In a trifle bowl add a layer of bite-size cake pieces, then top with half of the icing and half the Butterfingers. Repeat these layers to finish with Butterfinger on top.
Let this chill in the fridge for at least 1 hour before serving.
Notes
As of the writing of this post in 2023, Butterfinger Candy Bars are marked Gluten-Free with the exception of the Crisp. This recipe uses original Butterfinger Bars.If you do not need this to be gluten-free and want to make this no-bake, buy an already made Angel Food Cake and continue on with the instructions from the baked standpoint.