Preheat your oven to 350°F
Tear the bread into 2 inch pieces and add to a large bowl.
Pour the egg/milk mixture over the bread. Add the raisins, and stir until most of the custard is absorbed. The bread will break up a bit, that's fine.
Bake in the preheated oven, uncovered, until a toothpick inserted into the center comes out clean, about 20-30 minutes. Remove the budin from the oven and cool in the pan at room temperate for about an hour, then wrap in plastic wrap and efrigerate until cold, 2 hours more.
Slice and serve cold.