• Position racks in the upper and lower thirds of the oven and heat the oven to 375 degrees F.
• Combine 1/4 cup of the oil, the garlic, and bread cubes in a large bowl. Toss to coat. Spread the cubes in a single layer on 2 large rimmed baking sheets. Bake just until golden brown, about 12 minutes. Allow the bread to cool on the baking sheet and then return to the bowl. Lower the oven temperature to 350 degrees F. (The croutons may be prepared up to 3 days in advance. Once cooled, cover the baking sheets tightly with plastic, or place the bread in an airtight container and store at room temperature.)
• Warm the Madeira in a 1-quart saucepan over medium-low heat, about 1 minute. Remove the pan from the heat, add the prunes, and allow to macerate until cool, about 30 minutes.
• Meanwhile, heat 3 Tbs. of the oil in a 12-inch skillet over medium-high heat until shimmering. Add the celery, shallot, 1tsp. salt, and 1/2 tsp. pepper and cook, stirring frequently, until softened, about 3 minutes. Using a fine-mesh strainer, strain the Madeira from the prunes and add it to the skillet, gently stirring until the alcohol dissipates, about 5 minutes.
• Add the celery mixture, prunes, and parsley to the croutons and toss to combine.
• Oil a 9×13-inch baking dish with the remaining 3 Tbs. oil. Beat the eggs in a medium bowl and then whisk in the chicken stock. Pour the egg mixture over the stuffing, add the apples, and toss to combine. Let the stuffing sit until the liquid is absorbed, about 10 minutes, tossing occasionally. Add additional stock 1/2 cup at a time if the stuffing seems dry. The bread should be moist but not soggy.
• Transfer the mixture to the prepared baking dish and bake until lightly browned and crisp on top, 35 to 40 minutes. Serve warm.

Tips:

• Use a blended Madeira for cooking.
• A longer aged wine will have a deeper, nuttier flavor, but any Madeira will add layers of complex and rich flavor.
• The pairing here with dried plums is a culinary classic.