Double wrap the layer in plastic wrap, keep at room temperature, and use within 24 hours. Or freeze the layer for up to a month. Defrost the layer before assembling the finished cake. Don’t be concerned if some of the crust from the outside of the layer pulls away with the plastic wrap—it won’t affect the outcome of the finished cake.
Split a vanilla bean and use the point of a paring knife to scrape out the tiny seeds. Add the seeds to the egg, egg yolk, and sugar mixture for the plain génoise.
© 2008 Nick Malgieri. All rights reserved.