Sour-Cream Pancakes with Sour-Cream Maple Syrup

INGREDIENTS

• 1 tablespoon sugar
• 1/2 cup whole milk
• 1/2 teaspoon salt
• 1 cup all-purpose flour
• 1/3 cup pure maple syrup
• Scant 1/2 cup sour cream
• 1 teaspoon baking soda
• 2 tablespoons unsalted butter, melted, plus additional for cooking pancakes
• 1 large egg
• 1/2 cup sour cream
• 3 tablespoons unsalted butter, cut into pieces