Prepare the sponge cake recipe by following the recipe then cut it in 2 layers with a cake leveler.
Prepare the pastry cream recipe following the recipe and let it cool completely in the refrigerator.
Whip the pastry cream with a mixer to soften it, then gently fold in the whipped mascarpone frosting with a spatula until you have a smooth diplomat cream.
Place the strawberries halved on the outline of a cake ring then place a first layer of sponge cake. Then fill with the diplomat cream until the strawberries are completely covered.
Add the fresh strawberries in chunks to the center of the cake.
Cover with diplomat's cream then put the last layer of sponge cake and cover again with cream. Let the fraisier rest in the refrigerator for 1 hour before decorating with the remaining cream and strawberries.
Enjoy the strawberry fraisier.