Maple Pecan Chocolate Squares from Back to Baking by Anna Olson

Ingredients

• ¼ tsp (1 mL) salt
• ½ cup (125 mL) icing sugar, sifted
• 1¼ cups (310 mL) all-purpose flour
• ½ tsp (2 mL) baking powder
• 1 Tbsp (15 mL) cornstarch
• ½ cup (125 mL) packed dark brown sugar
• ½ cup (125 mL) cool unsalted butter
• ¼ cup (60 mL) unsalted butter, melted
• ½ cup (125 mL) pure maple syrup
• 2 eggs
• ¼ tsp (1 mL) ground cinnamon
• 2 cups (500 mL) pecan halves
• 1 tsp (5 mL) white vinegar or lemon juice
• 1 tsp (5 mL) vanilla extract
• 1 cup (250 mL) chocolate chips