Whisk together the egg, milk, sugar, cinnamon, and cardamom in a shallow bowl.
Dip the bread slices into the mixture, ensuring they are coated on both sides.
Melt the butter in a frying pan over medium-high heat and cook the bread for a few minutes on each side until golden brown and crisp.
Split the vanilla pod lengthways and scrape out the seeds. In a bowl, combine the mascarpone, Greek yoghurt, vanilla seeds, and Nicolas Vahé Vanilla Syrup until smooth and creamy.
Serve the warm French toast with a generous spoonful of mascarpone cream and a spoonful of jam on the side.
Finish with an extra drizzle of Nicolas Vahé Vanilla Syrup, if desired.