Lemon Custard Cake

• 6 egg yolks
• 6 egg whites
• 1 gelatin (unflavored)
• 1 commercial angelfood cake
• 300 gr sugar
• 180 ml squeezed lemon juice (freshly)
• 150 gr sugar until (thick)
• 150 gr sugar
• 60 ml water (cold)
• 3 gr lemon rind (grated)