Rinse strawberries under cool water, remove stems, cut into halves or quarters, and blend into a puree.

In a mixing bowl, beat heavy cream using an electric mixer until soft peaks form, about 2-3 minutes.

Gently fold strawberry puree into the whipped cream and sprinkle in sugar, adjusting to taste.

Add vanilla extract to the mixture and fold in carefully.

Spoon mousse into serving glasses, filling them about two-thirds full, and refrigerate for at least 1 hour to chill.

Remove from fridge and garnish if desired before serving immediately.