Polish apple pie with meringue

I have prepared quite a few apple pies, but I will definitely remember this one.
It successfully harmonizes the apple filling with lemon sourness and a sweet protein layer.
I recommend starting the preparation of this pie with the filling, because it will need to cool completely before the pie is assembled.
To do this, peel the apples and three on a coarse grater. We put it in a saucepan or saucepan. Add sugar and lemon juice. Put on medium heat and simmer, stirring occasionally, for about 15 minutes, until the filling becomes soft and the juice evaporates.
Beat stewed apples with a mixer (not a blender, the filling should not turn into applesauce), add the zest of one lemon, mix and leave to cool.
Next, we proceed to the preparation of the dough. To begin with, we separate the whites from the yolks. We will need proteins to make souffles, but for now it is better to put them in the refrigerator, because they are better whipped when cooled.
Add soft margarine to the yolks and beat with a mixer. Add flour and baking powder. Knead the dough. It is not necessary to knead for a long time so that the margarine does not begin to melt. Divide the dough into two parts: a larger and a smaller one. We send the larger one to the refrigerator, and divide the smaller one in half and send it to the freezer.
To prepare a layer of meringue, you need to beat the whites into a strong foam. In several steps, add sugar, while continuing to beat. You should get a smooth mass with stable peaks.
I recommend taking the shape with a diameter of about 26 cm. with removable sides, the pie turns out to be insanely tender and it is difficult to take it out of the mold and transfer it to a dish. If you want a taller pie, you can take a smaller diameter mold, but then increase the baking time by about 10 minutes.
Let's start assembling the pie. Roll out the dough from the refrigerator into a circle with a diameter larger than your shape, so that it remains on the sides. We transfer it to the mold, straighten it out forming high sides.
We spread the apple filling on the dough, level it. We take out half of the dough from the freezer and grate on top of the apple filling.
We spread the protein layer, distribute it evenly. Rub the remaining dough.
Bake in a preheated oven for about 30 minutes at a temperature of 180 degrees. If you took molds of a smaller diameter, the baking time should be increased.
It is better to leave the finished cake after cooking in a switched-off oven with the door ajar for 30 minutes.
Before you transfer the pie to a dish and cut it, you need to cool it completely.