Preheat oven to 350°F (175°C). Toss strawberries with 2 tsp granulated sweetener and 1/4 tsp vanilla extract. Spread on a baking sheet and roast for 15-20 minutes, or until softened and slightly caramelized. Let cool completely.

In a large bowl, beat softened mascarpone cheese and cream cheese until smooth and well combined for about 2 minutes.

Add powdered sweetener and 1 tsp vanilla extract to the cheese mixture, beating until fully incorporated and smooth, approximately 1 minute.

In a separate cold bowl, whip the heavy cream until soft peaks form, about 3-5 minutes.

Gently fold the whipped cream into the mascarpone mixture until no streaks remain and the mousse is light and airy.

Divide the mousse among serving glasses or bowls. Chill for at least 30 minutes to an hour before serving.

Top with the cooled roasted strawberries before serving.