Preheat your oven to 325º.

If you're planning to plump the raisins, now is a good time to get them soaking in the Grand Marnier. Use just enough to cover the raisins and let soak for about 30 minutes.

Place bread cubes in a bowl and drizzle with melted butter.

Grease ramekins with butter. You will need a large roasting pan to hold the ramekins.

Line the roasting pan with a dishtowel. This will keep the ramekins from slipping when you're moving the pan in and out of the oven. Spread the cubes on a baking sheet and toast until just golden, 8- 10 minutes.

Bring milk to a simmer over medium heat. In a large bowl, whisk whole eggs, egg yolks, and sugar. Gradually add in hot milk, continuing to whisk. Stir in vanilla.

Add half the breadcrumbs to the ramekins. Top with half the raisins. Repeat the layers again.

Ladle the egg mixture over the bread cubes and raisins. Let the bread stand for 20 minutes to absorb the custard.

Bring a kettle of water to a boil.

Place the ramekins on the towel in the roasting pan. Add enough boiling water to cover just halfway up the ramekins. 

Bake the puddings in the middle of the oven for about 45 minutes. They are ready when set. 

Carefully remove the roasting dish from the oven. Remove dishes. Let cool slightly.

Sprinkle with powdered sugar and serve warm.