Mix all cherry design ingredients until smooth. Divide batter into 3 small bowls. Color one red, one green and one brown. Place into 3 separate pastry bags. Line a 10" x 10" pan with parchment paper and grease with a small amount vegetable oil using a paper towel. Gently rub onto parchment. Snip off pastry bag points (make sure the brown one is a very tiny hole) and pipe tiny cherries and leaves onto parchment. Use a template underneath, if needed. Place in fridge for 5 minutes. Then pipe very thin lines for the brown stems. Put back in fridge while you make the cake batter.
For cake roll batter
With an electric mixer, beat the egg yolks and 2 T. sugar until pale yellow. Add water, oil and vanilla. Mix to combine. With mixer on low, gradually add the cake flour. In a separate bowl, beat the egg whites and remaining 2 T. sugar until stiff peaks. Fold into cake batter mixture. Pour into a pastry bag. Pipe batter carefully around the cherries. Tap pan gently to release bubbles. Bake at 350°F for 12 minutes.
Flip the pan immediately after baking onto a fresh sheet of parchment paper. Peel off the paper to reveal pattern. Flip over again and peel of paper. Add a fresh piece of parchment and let cool. Score the cake by very gently dragging knife across cake every 2 inches, not pressing down. Note, you will not actually cut the cake. This just makes it easier to roll.
Beat whipping cream with 2 tablespoons sugar. Spread onto cake. Add chopped strawberries. Gently roll cake. Refrigerate for an hour. Trim edges. Slice and serve.
Video
Notes
Cherry template: Draw cherries on a 10" x 10" piece of paper. Then slip that piece of paper under the parchment paper before you pipe the cherries.