Melt the butter in a saucepan and use some to grease a 23cm springform tin lined with parchment.
Crush the digestive biscuits into fine crumbs using a freezer bag and a rolling pin.
Stir the crumbs into the butter, press firmly into the tin, and chill for at least 30 minutes.
Preheat your oven to 180°C.
Separate the eggs carefully into bowls to ensure no yolk contaminates the whites.
Beat the cream cheese with the vanilla seeds until the mixture is smooth.
Beat in the sugar, followed by the eggs, extra yolks, and half of the crème fraîche.
Wrap the chilled tin in foil, place it in a roasting tin, and add the cheesecake filling.
Pour boiling water into the roasting tin and bake at 180°C for 10 minutes, then at 140°C for 45 minutes.
Turn off the oven and let the cheesecake cool inside with the door ajar before chilling thoroughly.
Blend half the strawberries with icing sugar to make a sauce and slice the remaining berries.
Remove the cheesecake from the tin, spread with remaining crème fraîche, and top with strawberries and sauce.