Preheat oven to 350 F degrees. Line a deep 9x13 inch baking pan with parchment paper.
In a large bowl, empty the contents of the box of angel food cake and to it add the lemon pie filling. Whisk it until it's well incorporated, you'll notice it start to foam a bit.
Pour the batter in the baking pan and bake for 30 to 40 minutes. I baked mine closer to 40 minutes, at 30 minutes it was not yet done.
You will want to use a very deep baking pan here, or at least cut the parchment paper so that it comes up the sides of the pan, so that the cake batter doesn't spill as it bakes.Please keep in mind that nutritional information is a rough estimate and can vary greatly based on products used.