In a bowl put 500g peeled and sliced feijoas with 1 tbsp sugar and zest of 1 lemon.
Cream 180g butter with 1 cup of sugar. Add 1 egg, 1 tsp vanilla and juice of 1 lemon.
Add 2 cups flour, 1 tsp baking powder and mix into a soft dough.
Spread most of the dough into a greased flan dish. Drain the feijoas and place on the dough.
Spread the rest of the dough roughly on the top, sprinkle with brown sugar.