Chocolate Bread Pudding - Once Upon a Chef

Ingredients

• 4 ounces semi-sweet chocolate
• 2 cups whole milk
• 1 cup sugar
• 2 tablespoons cocoa powder
• 3 tablespoons unsalted butter
• 2 tablespoons bourbon
• ½ teaspoon cinnamon
• 4 large eggs
• ¼ teaspoon salt
• 1 teaspoon vanilla extract
• 4 cups packed 1-in (2.5-cm) challah cubes (about 9 oz/255 g), from 1 loaf
• Vanilla ice cream (for serving)