peach cupcakes with brown sugar frosting

INGREDIENTS

• 3 cups cake flour
• 1 1/2 teaspoons baking powder
• 1 1/2 teaspoons baking soda
• 1 teaspoon salt
• Pinch of nutmeg
• 3/4 cup (1 1/2 sticks or 6 ounces) unsalted butter, at room temperature
• 3/4 cup granulated sugar
• 3/4 cup dark or light brown sugar, packed
• 2 large eggs, lightly beaten
• 1 teaspoon vanilla extract
• 1 1/2 cups (12 ounces) buttermilk, sour cream or full-fat yogurt
• 3 large peaches, peeled, cored, and chopped smallish (I went for a 1/3-inch dice)
• 1 1/4 cups light brown sugar
• 1/4 cup cornstarch
• 1/2 cup powdered sugar
• 2 8-ounce packages of cream cheese, at room temperature
• 1/2 cup (4 ounces or 8 tablespoons) unsalted butter, at room temperature
• 1/2 teaspoon vanilla extract