Scoop out the centre of each cooled cake using a small, sharp knife to leave a deep cavity in each cake.
Hull the strawberries and reserve 6 of the smallest. Thinly slice the remainder.
Whip the cream, sugar and vanilla extract with a handheld electric whisk in a bowl until just peaking. Spoon a little into the centre of each cake and flatten slightly with the back of the spoon.
Arrange the sliced strawberries, overlapping, around the edges of each cake. Halve the reserved strawberries and place a strawberry half in the centre of each cake.
Heat the redcurrant jelly with the water in a small, heavy-based saucepan until melted, then brush over the strawberries using a pastry brush. Store the cakes in a cool place until ready to serve.