Lightly grease six 150ml ramekin dishes or dariole moulds with sunflower oil.
Soak the gelatine leaves in cold water for 10 minutes.
Heat milk, cream, sugar, cinnamon, teabags, and cardamom seeds over low heat until boiling.
Dissolve the softened gelatine into the warm milk mixture.
Strain the mixture through muslin and pour into the prepared moulds.
Chill the panna cottas in the fridge for at least four hours until set.
Beat butter and icing sugar until fluffy, then fold in flour, egg whites, and vanilla.
Chill the biscuit batter in the fridge for one hour.
Preheat the oven to 180°C and line a baking tray with silicone paper.
Spread thin discs of mixture onto the tray using a 5cm template and sprinkle with cardamom.
Bake for 5-10 minutes until golden-brown at the edges.
Wrap warm biscuits over a rolling pin to curl and allow to cool.
Unmould panna cottas using boiling water and serve with the biscuits.