Preheat your oven to 350 degrees, spray with baking spray, and line a 13x18 baking sheet with parchment paper. Using a standing mixer with the whisk attachment, beat the egg whites, lemon juice, and salt until foamy. Gradually whisk in the sugar. Continue to beat until the mixture forms soft peaks. Gently fold in the cake flour until combined and smooth.

Divide the cake batter into 4 bowls and mix in a few drops of each color to get a nice vibrant shade. Mix in a few more drops to get the shade that you prefer. Alternate between all 4 colors, and drop dollops of the batters onto the parchment paper. Using a flat spatula, spread evenly.

Bake in the oven for 12 minutes or until it springs back at you! Remove and let the cake cool for 5 minutes before flipping the pan over onto another sheet of parchment paper. Remove the top layer of parchment paper and tightly roll the cake into a spiral. Place into the fridge and allow to cool for a few hours.

Using the standing mixer, beat the cream cheese, butter, powdered sugar, and vanilla until combined and smooth. Once the cake is chilled enough, carefully unroll the cake and frost the entire top of the cake in the cream cheese frosting, ensuring to spread it evenly. Carefully re-roll the cake. When ready to serve, dust the entire cake in powdered sugar. Enjoy!