In a saucepan over low heat, combine half the berries, sugar, lemon and vanilla.
Stir and cook for 3-4 minutes until the sugar melts and the fruit releases its juice.
Remove from the heat and add the remaining berries, stirring them into the hot liquid to melt slightly.
Strain the juice into a small bowl and set aside.
To assemble the pudding, cut one slide of bread into a rough circle to fit the bottom of the bowl.
Cut the other slides of bread in half so that you have strips of bread.
Dunk the bread into the fruit juice and layer it around the outer surface of the bowl lengthwise, bottom to top, overlapping slightly to line the bowl completely. Press the soaked bread down gently to secure them in place.
Spoon the fruit mixture into the center of the bread-lined bowl and place the last slices of bread on the top to cover the fruit, then pour all remaining juice over the top.
Cover the top of the pudding loosely with plastic wrap, then find a plate that fits just inside the bowl rim and set it on top. Put a weight of any kind on top of the plate to press the pudding down--any condiment jar or item in your fridge with some weight will work.
Place the bowl inside a larger dish to catch any juice that seeps out while it rests.
Chill in the fridge overnight.
To serve remove the plastic wrap and put a large plate face down on the top of the bowl and invert it. You will feel the pudding come out easily onto the plate in one piece, give it a gentle shake if necessary.
Serve in slices with cold cream poured on top.