Wash the berries, put in a saucepan, add water, sugar, vanillin. Bring to a boil, boil for 5 minutes. Cover with a lid and leave to cool.
Rub the berries through a sieve and strain. You should get 350 g of juice.
Dissolve instant gelatin in juice and heat, but do not boil.
Pour a thin layer of jelly into the bottom of the mold and leave to harden. Put strawberries in the center on a layer of frozen jelly and pour the remaining jelly. Leave until completely dry.
Remove frozen jelly from molds. Decorate the Valentine card with a canape skewer.