Preheat oven to 200°C and grease a large roasting pan. Strain cherries through a sieve set over a small saucepan to collect juices. Add caster sugar to juices and bring to the boil over medium heat. Whisk in icing sugar mixture and cook for 6 minutes or until slightly thickened. Add cherries and lemon juice, and stir until combined. Set aside. Heat a large frying pan over medium heat. Spread both sides of bread with butter, then cook, in batches, for 2 minutes each side or until golden.
Place toasts in a single layer in roasting pan. Spoon over most of the cherry syrup, reserving a little to serve, then spoon over cherries. Bake for 15 minutes or until bread is well soaked and heated through.
Divide cherry bread pudding among plates, spoon over sour cream, scatter over roasted almonds and drizzle with remaining cherry syrup to serve.