In a medium saucepan, combine fresh raspberries, sugar, and lemon juice. Cook over medium heat for about 5–7 minutes, stirring gently until the mixture becomes syrupy.

Pour the cooked raspberry mixture through a fine-mesh sieve into a bowl to strain out the seeds, pressing to extract as much liquid as possible.

In a small bowl, sprinkle gelatin over cold water and let it sit for 5 minutes to bloom.

Gently reheat the strained raspberry puree until warm, then stir in the bloomed gelatin until fully dissolved.

In a large mixing bowl, beat the heavy cream with powdered sugar and vanilla extract until soft peaks form, about 3–5 minutes.

Fold the whipped cream into the raspberry mixture gently, maintaining its airy texture.

Spoon the mousse into serving glasses, cover with plastic wrap, and refrigerate for at least 3–4 hours until set.

Garnish with fresh raspberries or mint leaves before serving and enjoy!