Wash the cherries well and pit them. We weigh to obtain the 800 grams necessary for the filling of our cake or cherry pie. Put the pitted cherries and the sugar in a wide and deep bowl. Cover with plastic wrap and leave rest in the fridge between 8 and 10 hours.
We prepare the cake base following the instructions of our foolproof shortcrust pastry recipe, but without actually baking it. We will do this once it is filled with cherries and the cake is assembled. Reserve the dough in the fridge, divided into two halves (one slightly larger than the other) wrapped in plastic wrap.
When it is time to assemble the cake, we stretch the largest half of dough in a circular shape and place it in a 25cm mold, in whose base we will have placed a disc of vegetable paper. Remove the excess and store in the freezer while we continue with the recipe.
We stretch the other portion of dough, giving rectangular shape. With a zigzag cutter or a sharp knife, cut into strips one centimeter wide, cover with plastic wrap and also store in the freezer.
Add the refined cornmeal to the cherries, which will have released all their juice, and stir well until no lumps visible. Remove the base dough from the freezer and spread the filling on top. We take the other dough out of the freezer and form a lattice with the strips on the cherries.
Beat the egg and brush the lattice. We put the cake in the bottom from the oven, preheated to 220 ºC with heat below, and cook for 12 minutes. Then we lower the temperature to 200 ºC and cook between 35 and 40 minutes, depending on how golden it looks.
Remove the cake from the oven and leave cool completely before unmolding. It is a very fragile cake that must be handled with care. It is delicious on the day of preparation, but also a day or two later.