Nutella Shortbread Bars

Bahan-bahan (30 porsi)

• 1½ cups (3 sticks) butter, (at room temperature)
• 3/4 cup packed light brown sugar
• 3/4 cup granulated white sugar
• 2 teaspoons vanilla extract
• 3/4 teaspoon salt
• 3½ cups all purpose flour
• 1½ cups Nutella ((or another brand of chocolate hazelnut spread))
• powdered sugar