Tiramisu Cupcakes

INGREDIENTS

• 1 1/4 cups cake flour (not self-rising), sifted
• 3/4 teaspoon baking powder
• 1/2 teaspoon coarse salt
• 1/4 cup milk
• 1 vanilla bean, halved lengthwise, seeds scraped and reserved
• 4 tablespoons (1/2 stick) unsalted butter, room temperature, cut into pieces
• 3 large whole eggs plus 3 egg yolks, room temperature
• 1 cup sugar
• Coffee-Marsala Syrup
• Mascarpone Frosting
• Unsweetened cocoa powder, for dusting