In a medium saucepan over medium heat, combine chopped fresh strawberries, granulated sugar, and lemon juice. Stir frequently for about 8–10 minutes until strawberries soften.

Once the mixture is slightly cooled, pour into a blender and blend until smooth. This should take about 30 seconds.

In a small bowl, sprinkle unflavored gelatin over cold water and let sit for 5 minutes. Heat in the microwave for 10-15 seconds until melted.

Stir the melted gelatin into the cooled strawberry puree until evenly mixed.

Allow the mixture to cool completely at room temperature for 15-20 minutes.

In a large bowl, add cold heavy cream, powdered sugar, and vanilla extract. Beat with an electric mixer on medium speed until soft peaks form.

If desired, mix in a few drops of gel food coloring to enhance the mousse color.

Gently fold the cooled strawberry mixture into the whipped cream using a rubber spatula until just combined.

Transfer the mousse into a bowl, cover tightly with plastic wrap, and refrigerate for 30-45 minutes until slightly thickened.