To prepare the pear, walnuts, ricotta pie start peeling the four pears, preferably ripe, take away the central core and cut into small pieces. Put them in a bowl along with the chopped walnuts and with very little lime juice to prevent discoloring.
Preheat the oven to 160 degrees C (325 degrees F). In a large bowl, beat with a whisk (or a planet) sugar with ricotta. Add 3 eggs one at a time and continue beating the mixture.
Add the grated lime zest.
Sift the flour with the baking powder and add to the mixture, stirring with a wooden spoon until you get a smooth dough. If needed, use the whisk. Stir in pears and walnuts with ‘any sauce that had formed and mix well.
Pour into a cake pan with parchment paper.
Now bake the cake at 160 C (325 F) for 50/60 minutes, until introducing a toothpick in the center of the cake, these will be dry. In case the cake you were to darken too much on the surface during cooking cover with aluminum foil.
Remove the cake from the oven, let it cool, put it on a serving plate and if you wish sprinkle with powdered sugar before serving.