Make the genoise cake: In a large mixing bowl, using a handheld or stand mixer fitted with a whisk attachment, whisk eggs on medium speed just until combined. Add sugar and whisk on medium-high speed for about 10-12 minutes until white pale, foamy and tripled in size. (It takes 3-5 minutes longer with a handheld mixer compared to a stand mixer). To know if you have the right consistency, let a bit of batter drip off the whisk attachment on top of the mixed batter. The dripped batter should be visible for 10 seconds before it sinks into the batter. If it sinks earlier, you need to whisk longer.