01 - Preheat oven to 350°F. Grease a 9x13-inch baking dish with butter.
02 - Place bread cubes in a large mixing bowl. Pour milk and cream over the bread, tossing gently to coat evenly. Let stand for 10 minutes to absorb liquid.
03 - Whisk together eggs, sugar, vanilla, cinnamon, nutmeg, and salt in a separate bowl. Add melted butter and whisk until fully incorporated.
04 - Pour custard mixture over soaked bread. Add raisins and fold gently until bread is evenly coated and raisins are distributed throughout.
05 - Spread mixture evenly in the prepared baking dish, pressing down lightly to compact.
06 - Bake for 45 to 50 minutes until golden brown and set. A knife inserted in the center should come out clean. Allow to cool slightly while preparing sauce.
07 - Combine sugar and water in a medium saucepan. Cook over medium heat, swirling pan occasionally until sugar dissolves and mixture turns deep amber, approximately 8 to 10 minutes. Do not stir.
08 - Remove from heat. Carefully whisk in butter—mixture will bubble vigorously. Slowly add cream while whisking constantly until smooth. Stir in vanilla and salt.
09 - Serve bread pudding warm, generously drizzled with warm caramel sauce.