Start by preheating your oven to 400°F. While it heats, grab a large bowl and whisk together milk, eggs slightly beaten, sugar, melted butter, cinnamon, nutmeg, and salt. Whisk until the sugar dissolves and everything looks smooth.

Cube the bread. You need about 12 cups of bread cubes, roughly from 12 slices. Day-old bread works best because it's sturdy enough to soak up liquid without disintegrating. If your bread is fresh, toast it lightly or leave it out for a few hours to dry.

Add the bread and raisins. Toss the bread cubes and raisins into the custard mixture. Stir gently so every piece gets coated. Let it sit for 5 minutes. This is the step most people skip, and it's the reason their bread pudding comes out uneven.

Pour into the pan. Transfer everything into a greased 9x13 baking dish. Spread it out evenly, but don't press it down. You want air pockets for texture.

Bake uncovered. Slide the pan into the oven and bake for 45 to 60 minutes. You're looking for a toothpick inserted about an inch from the edge to come out clean. The top should be golden and slightly puffed.

Make the vanilla sauce while it cools. In a small saucepan, sugar, water, vanilla extract, and cornstarch. Whisk constantly over medium heat until the mixture starts to boil and thicken. When it coats the back of a spoon, pull it off the heat.

Serve warm. Spoon the vanilla sauce over individual servings while the pudding is still warm. The sauce soaks in slightly and adds a glossy sweetness that makes every bite feel indulgent.