1. Soak a gelatin envelope in cold water for 5 minutes.

2. Squeeze out the excess water and melt the gelatin in a saucepan with about 2 tablespoons (30 ml) of strawberry puree over low heat, approximately 150°F (65°C).

3. In a blender or food processor, combine 1 cup (200g) of strawberries and 1/2 cup (100g) of granulated sugar. Blend until smooth and creamy.

4. Add the remaining strawberry puree to the saucepan with the melted gelatin. Remove the saucepan from the heat and mix well.

5. In a separate bowl, whip 1 cup (240 ml) of heavy cream until stiff peaks form.

6. Fold the whipped cream into the strawberry mixture until well combined. Taste and adjust the sweetness by adding more sugar if desired.

7. Divide the mousse among four glasses or small cups. Refrigerate for at least 2-3 hours, or until set, at a temperature of around 40°F (4°C).

8. Top the mousse with additional whipped cream, sliced strawberries, and crushed cookies or wafers, if desired.