Begin by sprinkling one packet of gelatin over 2 tablespoons of cold water in a small bowl. Let it sit for about 5-10 minutes.

In a medium saucepan, combine 10 ounces of raspberries, 1/2 cup sugar, and 2 tablespoons lemon juice. Cook over low heat for 5-10 minutes, stirring occasionally.

Once cooked, strain the mixture through a fine mesh strainer into a clean bowl, pressing out liquid while leaving seeds behind. Stir in bloomed gelatin until dissolved.

Allow the raspberry syrup to cool to room temperature, about 15-20 minutes.

In a large mixing bowl, whip 2 cups of heavy cream with 1/4 cup of powdered sugar until stiff peaks form, about 3-5 minutes.

Gently fold in 1/4 of the whipped cream into the raspberry mixture to lighten it. Then fold in the remaining whipped cream carefully.

Spoon the mousse into serving dishes, cover with plastic wrap, and refrigerate for 1-2 hours until set.