To make the pasta frolla: Sift the flour, sugar, and salt together into a medium bowl. Using a pastry cutter or 2 dinner knives, cut in the butter until a crumb like mixture is formed. Using a fork, mix the egg mixture into the flour mixture until evenly moistened. Using your hands, gather about two-thirds of the dough into 1 ball and the remaining one-third into a second ball. Wrap each ball separately in plastic wrap and refrigerate for 1 hour or up to overnight before using.

Butter an 8-inch springform pan. Preheat the oven to 350°F.

Sprinkle a work surface lightly with flour and roll the larger ball of dough into a disk 1/8 inch thick. Place aluminum foil under the pan and crimp it around the sides of the pan to catch any leaks during baking. Fit the dough into the spring form pan and crimp the edges. If making a lattice crust, roll out the second ball of dough into a disk 3/8 inch thick. Using a fluted pastry wheel, cut it into strips about ½ inch wide. Refrigerate the dough-lined pan and the strips of dough until ready for use.

To make the filling: In a large bowl, beat the ricotta and mascarpone together until well blended. Stir in the ¾ cup granulated sugar and the flour. Beat in one egg at a time until each is fully incorporated into the mixture. Stir in the rum, chocolate, candied orange rind, cinnamon, and zests, and blend thoroughly.

In a deep bowl, beat the heavy cream with the 2 tablespoons granulated sugar until soft peaks are formed. Fold it into the ricotta mixture until blended. Pour the ricotta filling into the prepared pan and smooth the top evenly. Arrange the strips of dough in a diagonal lattice over the filling, trim where necessary, and pinch them onto the crust. Slide the pan onto the middle rack of the oven and bake until a skewer inserted into the center of the cake comes out clean, 1 hour to 1 hour and 15 minutes. Turn off the oven and leave the cake inside with the door closed for about 1 hour. Remove from the oven and let cool completely. Remove the sides of the springform pan. Slide the cake onto a cake platter. Cover with plastic wrap and refrigerate at least overnight before serving.

Before serving, dust the crostata with confectioners’ sugar. The crostata is usually cut into small slices and accompanied with espresso.