Tiramisu Cookies

Ingredients (16)

• 1 cup butter, softened
• 3/4 cup sugar
• 2 large eggs, room temperature
• 2 teaspoons rum extract
• 1 teaspoon vanilla extract
• 2-1/4 cups all-purpose flour
• 1 to 2 teaspoons instant espresso powder
• 1 teaspoon baking powder
• 1/4 teaspoon salt
• FILLING:
• 1 carton (8 ounces) mascarpone cheese
• 1/4 cup butter, softened
• 1 tablespoon Kahlua (coffee liqueur) or 1 teaspoon instant espresso powder (dissolved in 1 tablespoon hot water)
• 3 cups confectioners' sugar
• Dash salt
• Baking cocoa or Dutch-processed cocoa