Preheat the oven to 350 degrees.
In a medium bowl, mix the angel food cake batter according to package instructions.
Line a rimmed half sheet pan with parchment paper and evenly spread the batter throughout the pan. Avoid greasing the edges of the pan (greasing the bottom so that the parchment paper sticks is OK).
Bake for 20-25 minutes or until the top of the cake is light brown.
As soon as the cake comes out of the oven, run a knife along the edges to release the cake. Then generously sprinkle powdered sugar over the entire top of the cake.
Next, place a tea towel (or flour sack towel) over the cake/powdered sugar layer, then place an inverted cookie sheet (of similar size or smaller) on top. The bottom of the cookie sheet should be touching the towel.
Then gently press them together and flip the cookie sheets, removing the original cookie sheet.
Peel off the parchment paper and immediately (but gently) roll the cake up into the towel. Let the cake cool completely for about an hour, or in the fridge for 30-45 minutes. While it cools you can make the lemon cream filling.