Apple cupcakes with caramel frosting

Ingredients

• 1 1/2 cups all-purpose flour
• 1 teaspoon baking soda
• 1/4 teaspoon baking powder
• 1/2 teaspoon salt
• 1 teaspoon ground cinnamon
• 1/4 teaspoon ground nutmeg
• 1/2 cup unsalted butter, melted
• 2/3 cup packed brown sugar
• 1/3 cup granulated sugar
• 2 large eggs, at room temperature
• 1/3 cup milk, at room temperature
• 2 teaspoons pure vanilla extract
• 1 large apple, peeled and finely chopped
• 1/2 cup unsalted butter
• 5 Tablespoons heavy cream, divided
• 2 cups confectioners' sugar
• optional garnish