Preheat your oven to 180°C (160°C for fan-assisted ovens).

Roll out your ready-made shortcrust pastry on a lightly floured surface to fit your tart tin. Once rolled out, gently press the pastry into the tin, making sure to press into the corners.

Prick the bottom of the pastry with a fork to prevent it from puffing up during baking. Pop the tart tin into the oven and bake for 10-15 minutes or until lightly golden.

While the pastry is baking, whisk together the eggs and sugar in a mixing bowl until well combined.

Add the marmite to the egg mixture, whisking until it's thoroughly mixed in.

Pour in the melted butter, fresh cream, and vanilla essence. Continue to whisk the mixture until everything is well combined.

Once the pastry is done, remove it from the oven and carefully pour in the marmite mixture.

Pop the tart back into the oven and bake for about 30-35 minutes, or until the filling is set and slightly golden on top.

Allow the Marmite tert to cool a bit before slicing it up and serving.