Preheat oven to 350 degrees F. Grease a 9 or 10-inch spring-form cake pan. Cream together ricotta, butter and sugar until light; beat in the egg.
In another bowl, whisk together the flour, cornmeal, baking powder, salt and cinnamon. Mix into the ricotta mixture until just combined. Mix grated apple with lemon and then fold into the batter. Pour cake batter into the prepared pan and bake 40-45 minutes, or until golden brown and done in the centre. (Cake does not rise very much). Cool on a rack, and then transfer to cake plate. Garnish with apples an other fruit such as grapes and berries, dust with icing sugar, and serve.
Recipe Options: For a slightly, sweeter taste, use ripe, grated pear in the cake instead of apple. If you like spices, along with the cinnamon, include a pinch of ground cloves and nutmeg in the cake batter.