For the Sponge Cake: Preheat oven to 375°F. Butter only the BOTTOM of a 11.5 x 17.2 in. (29.2 x 43.6 cm) Texturra Performance Baking Pan.
Sift the flour and salt together, set aside.
In a stand mixer whip the egg yolks for 1 minute, then slowly sprinkle the sugar in while they whip on medium speed. Turn up the speed to high and whip until light in color and forms a ribbon when the whip attachment is lifted out of the mixture. (If you only have one mixing bowl and whip, then transfer the whipped yolks to a large bowl).
In a stand mixer whip the egg whites until foamy, then slowly sprinkle the sugar in while they whip on medium speed. Turn up the speed to high and whip until medium-soft peaks. Fold the whites into the yolks in three stages. See my Instagram video to watch me make this cake.
Fold the flour into the egg foam mixture.
Pour the batter into the prepared pan and use a Versa-Tools Universal Spatula to quickly spread the batter evenly over the pan. Bake for about 12-15 minutes or until golden brown on top and baked through when tested with a skewer. Run a knife gently around the edge of the cake to loosen and immediately invert the cake onto the confectioners' sugar dusted parchment. Roll the cake from the long edge to form a log. Cover with a slightly moistened dish towel. See my Instagram video to watch me prepare the cake.
To make the cherry sauce: Whisk together the sugar and cornstarch. In a saucepan cook the cherries until they start to release the juices. Add the vanilla, sugar, cornstarch. Cook over low heat until they come to a boil and the cornstarch turns translucent. Transfer to a bowl and place in the refrigerator to cool and thicken. This can be made a day ahead.
Whip the cream until soft-medium peaks. Scoop half the cherries into the whipped cream and gently fold them together using the Versa-Tools Squeeze and Pour Spatula.
See Swiss Meringue Buttercream recipe (linked above in blog post) for crumb coating and covering the cake.
To assemble the cake: Unroll the sponge cake and spread the cherry whipped cream over the top using the Universal Spatula, add a little more cherries over the cream, but save some for serving. Use the Versa-Tools Scoop and Chop Baker's Blade to cut the cake and filling into thirds. Use the same tool to roll the section into a log, then lift that log with the Baker's Blade to the next section and roll that section onto the cake to create a spiral. Repeat that with the last section of cake. Wrap the rolled cake tightly in plastic and refrigerate for several hours. This is best done the day before decorating.
Create a crumb coat on the cake following the directions in the Swiss meringue recipe linked in blog post above. Once the cake is thoroughly chilled, you can cover the cake with the final coat of buttercream. I used the Versa-Tools Scoop and Chop Baker's Blade to smooth the icing. Chill the cake until ready to decorate.
To decorate the cake: To make the royal icing, mix all the ingredients in a stand mixer with the paddle attachment on medium speed, until they are light, fluffy and no longer shiny. When not using the royal icing, store it with a damp towel over the bowl, so the icing won't harden. See my video on instagram to see how I pipe the flowers and vines on the cake.
Place the cake on the serving platter and decorate with the royal icing flowers. Allow the cake to come to room temperature and cut with a thin knife dipped in hot water.