Kris Kringle Bread Pudding

Ingredients

• unsalted butter, softened, for bowls and parchment paper
• 3/4 cup vanilla sugar or granulated sugar, plus more for bowls and sprinkling
• 1 1/3 cups armagnac or other good-quality brandy
• 7 ounces assorted dried fruits, such as peaches, apricots, and pears
• 7 ounces pitted prunes
• 5 cups heavy cream
• 2 cups half-and-half
• 2 whole cinnamon sticks
• zest of 1 orange
• 12 large egg yolks, lightly beaten
• 2 large loaves day-old brioche (1 pound each), cut into 1 1/4-inch cubes (18 cups)
• boiling water, for roasting pan
• sour lemon sauce