Chocolate Chunk Bread Pudding

Name: Chocolate Chunk Bread Pudding
Ingredients: 2 tablespoons unsalted butter, cut into small pieces, plus more for buttering the baking dish; 4 large egg yolks plus 3 large whole eggs; 2/3 cup sugar; 4 cups milk; 1 1/2 teaspoons pure vanilla extract; 1/4 teaspoon ground cinnamon; Pinch freshly grated nutmeg; Pinch fine salt; One 1-pound loaf sliced white bread, cut into 1-inch pieces and left out overnight to dry out; 1 cup chocolate chunks; [For Serving:] Whipped cream and chocolate shavings (optional)