Nectarine Cupcake

INGREDIENTS

• 1 1/4 cups all-purpose flour
• 1/2 teaspoon baking powder
• Salt
• 1/3 cup whole milk
• 1 teaspoon pure vanilla extract
• 6 tablespoons unsalted butter, room temperature
• 3/4 cup sugar
• 2 large eggs
• 2 medium nectarines, peeled, halved, pitted, and finely chopped (1 1/4 cups)
• 1 cup cold heavy cream
• 1/2 cup sour cream
• 3 tablespoons sugar
• 1 medium nectarine, halved, pitted, and very thinly sliced, for garnish