Pour almost all of the milk into a small saucepot and gently warm it over medium heat. Stir in the sugar, vanilla and spices or liqueur. Continue heating until the mixture just begins to simmer.
Meanwhile, sprinkle the gelatin powder over the remaining milk. Let it rest for a minute or two to allow the gelatin to begin to rehydrate and absorb moisture. Pour in the hot milk mixture and stir until the gelatin is completely melted and dissolves into the mixture.

Divide the mixture evenly between 6 small dessert moulds. To help the panna cottas release easily, lightly oil the moulds before filling them. (Have fun with the moulds. Look around the house: teacups and ramekins work best but even Styrofoam and plastic cups trimmed to size work well too.)

Refrigerate until firm, at least 2 hours or overnight. To release the panna cotta from its mould, gently loosen the edges, cover with a small plate, then flip over. Don’t worry about leftovers! There won’t be any.