In a medium saucepan, combine cranberries, granulated sugar, orange juice, orange zest, and 1/4 cup water. Simmer on medium heat for 8-10 minutes until cranberries burst and soften.

Transfer the cranberry mixture to a blender and blend until smooth; then pass through a fine-mesh sieve into a bowl to remove solids. Chill the cranberry puree in the refrigerator for at least 1 hour, or until very cold.

Sprinkle gelatin powder over 2 tablespoons of cold water in a microwave-safe bowl and let it sit for 5 minutes to bloom.

Microwave the bloomed gelatin for 10-15 seconds until fully dissolved and clear, stirring well.

In a large, chilled bowl, beat cold heavy cream with powdered sugar and vanilla extract until medium-stiff peaks form.

Once the cranberry puree is cold, gently stir in the dissolved gelatin, then gradually fold the cranberry-gelatin mixture into the whipped cream.

Spoon or pipe the cranberry mousse into individual serving cups or glasses.

Refrigerate for at least 3-4 hours, or preferably overnight, until the mousse is fully set.

Before serving, garnish with fresh cranberries, orange zest curls, or a mint sprig as desired.