Grease six tumbler glasses (230 ml) with baking spray.
Put 1 tablespoon of strawberry jam in each glass.
Beat the butter and sugar until frothy. Stir in the eggs one at a time. Sift the flour and baking powder over it, add the vanilla pulp. Mix everything well.
Spread the batter over the glasses.
Bake for about 25 minutes at 180 ° C. Close the jars immediately.
To serve, garnish with a few strawberries and dust with powdered sugar. Spoon the cake straight out of the jar.