Preheat oven to 350F
Butter and flour a 10-inch springform cake pan, shaking off any excess.
Put the ricotta and sugar in a large bowl of a stand mixer (or use an electric hand mixer) and mix well until the sugar is all incorporated and the ricotta is smooth.
In another bowl combine the chopped candied pineapple, lemon zest, lemon juice, 1 tablespoon dark rum, and the raisins with the egg yolks and mix well with a large baking wooden spoon. Add the ricotta and mix thoroughly. Fold in the flour and mix until smooth.
Fold in the egg whites thoroughly and pour the mixture into the buttered pan.
Bake until the top is golden brown and a thin knife inserted in the center of the cake comes out clean, 40 to 45 minutes.
Cool at room temperature, remove from the pan, sprinkle with confectioner’s sugar, and serve.