These squares are a tasty (but somewhat sticky) way to enjoy a treat. The combination of coconut with walnut makes these squares a delicious delight.
Combine flour, brown sugar and butter in a bowl with a pastry blender or by cutting butter into dry ingredients with two knives until the largest lumps are the size of peas. Pat mixture into the bottom of a 9-inch (2 L) square baking dish. Bake in a preheated 400°F (200°C) oven for 10 minutes. Remove from oven. Lower oven temperature to 350°F (180°C). While baking prepare topping.
Stir together brown sugar, flour, baking powder and salt. Add eggs, one at a time, stirring until blended. Add corn syrup, walnuts, coconut and vanilla. Pour mixture over Base. Bake until set and golden brown, 20 to 25 minutes.