In a large saucepan, cook the berries with sugar, water to barely cover, and cinnamon stick and/or lemon peel over low heat until the berries have burst and the mixture is syrupy, about 15 minutes. Remove from heat.
To build a bread pudding in a deep, round dish: Cover the bottom of the dish with a layer of bread, cut into irregular pieces to fit the dish; then spoon on the liquid and berries until the bread is soaked and purple. Add another layer of bread; douse it with berries, and so on, until the dish is filled. Pour the last of the liquid over the top and refrigerate with a weighted dish set on top.
Before serving, whip the cream, sweeten it with the sugar, and cover the pudding with a thick layer. Scoop out portions so that each person gets plenty of cream with the pudding. The pudding can be molded for a prettier look and inverted onto a plate. Coat the pudding with the whipped cream.