Preheat oven to 350°F.
Whisk together flour and 1/4 cup powdered sugar.
Cut butter into flour mixture until mixture looks like cornmeal.
Pat into 9" square pan and bake for 15 minutes.
Combine granulated sugar, kiwifruit, eggs, lime juice, lime zest & baking powder.
Pout over baked crust, return to oven.
Bake an additional 25 minutes.
Cool and sprinkle with remaining powdered sugar.
Cut into 16 squares and serve.