Combine water, lemon zest, thyme, and sugar in a saucepan.

Bring the mixture to a boil.

Boil for one minute, then remove from heat.

Strain lemon juice to remove seeds and pulp.

Add limoncello to the strained lemon juice.

Combine the zest and cooled sugar mixture with the juice and limoncello mixture.

Stir to mix and chill the mixture in an ice bath for 3 hours.

Pour the chilled mixture into an ice cream maker and freeze according to the manufacturer's instructions.

Mash raspberries with a fork until soft.

Add sugar to the mashed raspberries and mix well.

Hollow out the squeezed lemon halves, removing the insides with a knife.

Cut a small slice off the bottom of each lemon so they stand up.

Spoon raspberry puree into the lemon cups.

Top with lemon sorbet.

Garnish with a raspberry.

Return to the freezer for at least two hours.