Fill a large saucepan with a few inches of water and bring to a simmer over medium heat.
In a large heat-proof bowl, whisk together 3 whole eggs, 3 egg yolks (reserve the whites in a separate bowl), 1 cup sugar, lemon zest, lemon juice, and a pinch of salt.
Place the bowl over the pan of simmering water and cook, stirring constantly with a wooden spoon, for about 15 minutes, or until mixture thickens slightly.
Remove from heat and set aside for 15 minutes. Pour into a bowl and place a piece of plastic wrap directly on the surface of the mixture. Refrigerate for at least 1 - 2 hours or until completely chilled.
Place the 3 remaining egg whites in a mixing bowl and beat on high speed for 1 minute. Add remaining 2 tablespoons of sugar and continue to beat until the whites are stiff. Carefully fold the beaten whites into the cold lemon mixture.
Add the cream to a bowl and beat on high speed until stiff peaks. Fold the whipped cream into the lemon mixture.
Chill for at least 30 minutes and serve cold. Store in the fridge for up to 5 days.