For the Cookies:

• 1 ¾ cups all-purpose flour
• 1 teaspoon baking powder
• ½ teaspoon salt
• 2 tablespoons instant espresso powder
• ½ cup unsalted butter, softened
• ½ cup granulated sugar
• ½ cup brown sugar
• 1 large egg
• 1 teaspoon vanilla extract
• ¼ cup brewed espresso or strong coffee, cooled

For the Mascarpone Filling:

• ½ cup mascarpone cheese, softened
• 2 tablespoons powdered sugar
• ½ teaspoon vanilla extract

For Dusting:

• 2 tablespoons unsweetened cocoa powder