- Preheat oven to 180C (350f). Line a 10”x15” cake sheet with parchment paper.
- Mix eggs until light in colour and frothy, about 5 minutes. Add sour cream, water, oil, and cake mix. Mix on low until combined. Stir with a spatula gently.
- Split batter into three. Add red food colouring to one bowl and green to another. Place all three into individual piping bags with small holes cut at the tip.
- Pipe alternating batters, vanilla, red, vanilla, green, vanilla etc lines diagonally across the pan. Use remaining batter for another pan or for cupcakes/donuts etc.
- Tap pan on the counter about 3 times to pop any air bubbles. Bake in the oven for 7-8 minutes until cake is spongy and springs back slightly when touched.
- While hot, flip cake carefully onto a dish towel. While still warm, roll with the towel tightly but carefully. Set aside to cool for about 30-40 minutes.
- While cake Is cooling make the icing, whip together cream cheese, whipping cream and icing sugar until stiff peaks form.
- Unroll cake gently, spread cream cheese mixture evenly leaving 1/2" at the end. Roll evenly and tightly. Set in the fridge for 30 minutes.