Baci di Dama Italian Cookies

Bahan-bahan (20 porsi)

• 2 cups hazelnuts (roasted, skinned (2 cups = 240g))
• 1 cup all-purpose flour
• 2/3 cup granulated sugar
• 4 Tbsp corn starch
• 1/4 tsp salt
• 5 oz cold unsalted butter (cut to small pieces)
• 2 tsp vanilla extract
• 1 cup semi-sweet chocolate chips