1) Place the ice cream in a mixing bowl and add the jam. Using a rubber spatula, fold in the jam so it forms streaks through the ice cream and is not uniformly mixed. Return the mix to the ice cream tub and freeze until set, about 2 hours.
2) Melt the butter in a small pan over a medium-high heat. Add the bread cubes and stir to coat the bread on all sides. Continue stirring, until the bread is golden brown all over.
3) Remove the bread croutons from the heat. Sprinkle with 3 tbsp of sugar and set aside.
4) Combine the double cream and brown sugar in a saucepan and bring to the boil. Reduce the heat to simmer, add the peanut butter and stir until combined and melted.
5) To serve, scoop the ice cream into serving bowls, drizzle with peanut butter sauce and top with croutons.