Prepare the sponge cake:
- Preheat the oven to 350°F (175°C)
- Separate the egg whites from the yolks
- Soak the gelatin sheets in cold water to soften

In a mixing bowl, beat the egg yolks with the sugars until the mixture is pale, then add the flour, cornstarch, and baking powder. Mix well.

Beat the egg whites with the salt until stiff peaks form, then gently fold them into the batter in thirds.

Pour the batter onto a silicone baking mat and bake for about 15 minutes.

Make the strawberry sauce:
- Wash and hull the strawberries
- Blend them with the lemon juice, add the sugar, and blend again
- Bring the sauce to a boil in a saucepan, then add the 2 softened gelatin sheets. Set aside.

Prepare the cream:
Beat the yogurt with an electric mixer on high speed for 3 minutes to aerate.

Add the whipping cream and beat until stiff peaks form, then add the whipped cream stabilizer if using.

Add the sugar and vanilla extract.

Gently fold in the strawberry sauce.

Assembly:
- Cut out and place a round of sponge cake in each parfait glass
- Spoon the strawberry mousse over the sponge cake
- Finish with the cooled strawberry sauce and chill for at least 4 hours.