In a small bowl, soak the gelatin sheets in 1/2 cup of cold water. Set aside.
In a medium-large sauce pot bring the strawberries and sugar to a simmer. Cook until the strawberries are soft, then use an immersion blender to puree the fruit.
Squeeze the excess water from the gelatin sheets and add them to the strawberry mixture.
In a medium-large sauce pot, bring milk, 1/4 cup of sugar, butter, salt and vanilla to a simmer.
Whisk together cornstarch and remaining sugar. Add eggs and yolks, mixing into a smooth paste.
Slowly, and in small amounts, whisk the hot milk into the egg mixture. Once the egg mixture is warm to the touch, whisk back into the remaining milk in the pot.
Bring the mixture to a boil, whisking continuously for 3 minutes. Whisk in the strawberry mixture until smooth.
Pour into a shallow container, cover with plastic wrap directly on the surface of the pastry cream and set in an ice bath until cool, stir every 15 minutes so the gelatin doesn’t set too hard before folding in the whipped cream.
Once the pastry cream is cooled to room temperature, stir until smooth, then fold in the whipped cream. Chill for at least 3 hours or overnight.