In a medium saucepan, combine ½ cup of unsalted butter, 1 cup of granulated sugar, the zest of 2 lemons, and ½ cup of freshly squeezed lemon juice. Stir continuously for about 8 minutes until thickened. Remove from heat, cool, and refrigerate.

In a heatproof bowl, whisk together 4 large eggs, ½ cup of granulated sugar, the zest of 1 lemon, ½ cup of freshly squeezed lemon juice, and a pinch of salt. Place over simmering water and whisk for about 12 minutes until thickened. Cool and refrigerate.

Beat 4 egg whites with a pinch of salt until soft peaks form, about 3-5 minutes. Gradually add ¼ cup of granulated sugar while continuing to beat until stiff peaks form, about another 2-3 minutes.

Gently fold the whipped egg whites into the chilled lemon filling, then add the chilled homemade lemon curd and fold until uniform.

Whip 1 cup of heavy cream until soft peaks form. Gradually add 2 tablespoons of powdered sugar and 1 teaspoon of vanilla extract, whipping until stiff peaks form.

Cover the Fresh Lemon Mousse and chill for at least 2 hours. Serve topped with whipped cream and optionally garnish with fresh berries or mint.