In a medium saucepan over medium heat, combine chopped ripe strawberries, granulated sugar, and freshly squeezed lemon juice. Cook for 8–10 minutes, stirring occasionally.

Remove from heat and allow to cool slightly for about 5 minutes. Puree the mixture until smooth.

In a small bowl, sprinkle unflavored gelatin over cold water and let it bloom for 5 minutes. Then heat gently until melted.

Stir the melted gelatin into the cooled strawberry puree until well combined.

Allow to cool to room temperature for 15–20 minutes.

In a chilled mixing bowl, combine heavy whipping cream, powdered sugar, and vanilla extract. Beat until soft peaks form, about 3–4 minutes.

If desired, mix in gel food coloring to the whipped cream.

Carefully fold the cooled strawberry mixture into the whipped cream without deflating it.

Transfer the mousse filling into a bowl, cover with plastic wrap, and refrigerate for 30–45 minutes until it thickens slightly.