Separate the eggs. Mix the egg yolks and sugar in a bowl until frothy. Stir the grated lemon zest, almonds and quark into the egg yolk mixture. Beat the egg white until frothy and finally fold it into the egg yolk mixture. Pour the mixture into ovenproof molds and place a peach or an apricot on top. Bake in the oven for about 60 minutes. Sprinkle with powdered sugar and serve warm.