**Bloom the gelatin (optional)** If you want a firmer mousse, sprinkle the unflavored gelatin over 1 tablespoon of water in a small dish. Let it sit for 5 minutes to bloom, then microwave for 5–10 seconds to dissolve. Allow it to cool slightly.

**Whip the cream** In a mixing bowl, beat the cold heavy cream on medium speed until it starts to thicken. Add the powdered sugar and continue beating until soft peaks form.

**Add lemon** Gently fold in the lemon juice and lemon zest. If using gelatin, slowly drizzle it in while folding. Adjust sweetness if desired.

**Check consistency** Beat or fold just until the mixture holds firm peaks, being careful not to overwhip. Overmixing can cause the cream to separate.

**Chill** Divide the mousse into individual cups or a serving bowl. Cover and refrigerate for at least 2 hours, allowing the flavors to meld and the mousse to firm up.

**Serve** Garnish with additional lemon zest, mint leaves, or a dollop of whipped cream before serving.