Start by melting the butter. Break the Petit Beurre cookies down into a fine crumb, using a pestle and mortar or a blender. Add the melted butter.
Tip the mixture into a cake ring, placed on a sheet lined with baking parchment. Press the mixture down firmly so that the whole surface is even; you can use the base of a glass to help you with this.
Soak the gelatin sheets in cold water.
Separate the egg yolks and whites. Whisk the egg yolks with the sugar until the mixture turns white.
Mix the cheese and the cream together in a bowl. Slice the vanilla pod in two lengthwise and remove the seeds. Add them to the cheese mixture.
Wring the gelatin sheets to remove excess water, then melt them in 2 spoonfuls of hot water. Add them to the cheese mixture and mix thoroughly. Set aside.
Whisk the egg whites until they form stiff peaks.
Gently incorporate them into the mixture.
Wash and hull the strawberries, then cut them lengthwise. Arrange a dozen of them around the edge of the ring. Pour the mixture over the top. Place some more strawberries in the center. Keep a few for decoration.
Smooth and even out the surface. Chill for at least four hours.
When it is time to serve your cheesecake, pass a thin knife blade around the cake ring if needed, and gently remove it. Decorate with the remaining strawberries.