Preheat oven to 350 F (180 C). Grease and line a quarter sheet pan with parchment paper.
Make the crust. Combine the flour and powdered sugar and pulse a few times. Add the butter then pulse a few more times until a soft ball of dough is formed. Flatten the dough with floured hands and press it into the baking sheet. Bake for 15 to 20 minutes until very lightly browned.
Meanwhile, prepare the filling. Boil the water in a saucepan. Add the dried mangoes and cook for 10 minutes or until soft. Drain the mangoes and roughly chop them.
In another bowl, whisk together the flour, baking soda, and salt.
In a separate bowl, combine the eggs, vanilla extract, white sugar, brown sugar, and chopped mangoes. Add the flour mixture, mixing until just combined.
Pour the mango mixture over the baked crust and spread evenly. Top with walnuts.
Bake for 22-25 minutes or until the center is set but not hard. Be careful not to overbake.
Let it cool completely before slicing them into 2x2 in (5 x 5 cm) squares.
Store in an airtight container at room temperature for up to 3 days, or keep in the fridge for up to 5 days.
Recipe by Kaleidoscope Living at https://designertrapped.com/delicious-mango-walnut-squares/