For 2.
Use a zester to remove about 1 teaspoon of Yuzu zest and set it aside for decoration. Finely grate the remaining peel. In a pan, bring the grated peel to a boil with cream, vanilla extract, and half of the sugar. Set aside.
Beat the egg yolks and remaining sugar in a stainless steel bowl with a hand mixer for about 5 minutes until light and frothy. (this may take longer) Continue stirring over a bain-marie until the cream warms up.
Reheat the yuzu cream in the pan and slowly pour it into the whipped egg mixture, stirring constantly. Continue whisking until the foam thickens and the whisk leaves visible traces.
Remove the bowl from the bain-marie. Keep whisking the cream until it cools slightly. Squeeze the yuzu juice and stir it into the mixture. Distribute the cream into glasses and chill.