Perfect Popovers with Cranberry Butter

Bahan-bahan (6 porsi)

• 6 teaspoons salted butter
• 1 1/2 cups whole milk, warmed
• 3 large eggs, at room temperature
• 1 tablespoon salted butter, melted
• 1 1/2 cups all purpose flour
• 1 teaspoon kosher salt