Defrost the raspberries. For the rim, squeeze lemons and pour juice, except for 2 tbsp, into a deep plate. Mix 2-3 tbsp sugar and 1 heaped tsp pepper on another plate. Dip four champagne glasses one after the other with the rim first in lemon juice and then press them into the sugar-pepper-mix.
Allow to dry.
Wash the thyme and shake dry, pluck the leaves. Puree the raspberries and pass through a sieve. Mix with syrup, 2 tablespoons lemon juice and vodka. Divide into the glasses, fill up with prosecco and sprinkle with thyme.