Homemade Milano Cookies

Ingredients

• Cookies
• 1 stick (8 tablespoons) unsalted butter, at room temperature
• 2 cups confectioners' sugar
• 1 teaspoon pure vanilla extract
• 4 egg whites
• 1½ cups all-purpose flour
• ¾ teaspoon salt
• Chocolate Ganache
• 1 cup chopped chocolate
• ½ cup heavy cream