Heat oven to 325 degrees

In a large mixing bowl, combine cake mix, sugar and flour. Mix to combine.

Add in water, eggs, vanilla extract, and yogurt to the dry ingredients and mix well using an mixer. Mix for approximately two minutes.

Line bottom of two 10x15-inch jelly roll pans with parchment paper sprayed with baking spray.

Divide batter equally among 2 bowls.

Use red and blue color paste to each bowl of batter until you get a rich color. Paste will give a darker color than standard coloring. I like to use Wilton paste.

Pour batter into individual sandwich sized zip-lock bags, zip to close

Snip the tips off the bags and start layers of colored stripes at an angle across one pan. Alternate blue and red until complete. Continue until both pans are filled with stripes.

Bake for about 10 minutes.

Immediately flip cakes out of their pans, peel off the parchment paper, flip over onto a clean piece of parchment paper and immediately roll up the cake along with the parchment paper. Let it sit at room temperature for 10 minutes, then refrigerate for one hour or more until cool.

Make the filling by beating cream cheese, powdered sugar, butter, and vanilla until well blended.

When the cakes are cool, unroll carefully, peeling the parchment paper off as you go.

Spread half of the frosting over top of each cake, then tightly re-roll.

Refrigerate until ready to serve, cut into slices to serve.