Easy Bread Pudding

Name: Easy Bread Pudding
Ingredients: 1 (about 1-pound) loaf unsliced challah or brioche bread; 3 tablespoons unsalted butter, plus more for the baking dish; 4 large eggs; 2 large egg yolks; 1 medium orange or lemon (optional); 4 cups whole milk or half-and-half; 1 cup granulated sugar; 2 tablespoons vanilla extract; 1 teaspoon ground cinnamon; 1/2 teaspoon ground nutmeg; 1/4 teaspoon kosher salt; 1/2 cup dried fruit (such as raisins, cherries, cranberries, or chopped apricots) or chocolate chips (optional); Powdered sugar and/or vanilla ice cream, for serving (optional)