Chocolate Dipped Espresso Shortbread Cookies

Bahan-bahan (72 porsi)

• 1 cup (2 sticks) cold unsalted butter, (cut into ½ inch pieces)
• ½ cup granulated white sugar
• ½ teaspoon salt
• 2¼ cups (10 ounces) all purpose flour
• 2 tablespoons instant espresso powder
• 9 ounces semi-sweet chocolate, (chopped)
• 1 tablespoon shortening
• sprinkles ((optional))