2 cups milk
2 tablespoons unsalted butter plus more for greasing the pan
1 teaspoon vanilla extract
⅓ cup sugar
1 loaf Wise Sons challah, cut into 2-inch cubes (about 2 cups)
2 eggs, beaten
Heat oven to 350°F. Combine milk, butter, vanilla, sugar and salt in a small saucepan. Warm the mixture over medium-low heat until the butter is melted and the sugar has dissolved. Set aside to cool.
Meanwhile, grease a rectangular baking dish with butter and fill it with the cubed challah.
Add a couple of spoonfuls of the cooled milk mixture to the beaten eggs, whisking to combine. Whisk in a few more spoonfuls, then add the milk and egg mixture to the saucepan with the rest of the milk mixture. Pour the mixture over the cubed bread, making sure all pieces have absorbed at least some of the milk, and bake until custard is set and the edges of bread have browned, about 30 to 40 minutes.
Slightly adapted from Mark Bittman's "Simple Bread Pudding" from the New York Times.