Separate the eggs into egg yolks and egg whites. Egg yolks will be needed for the shortcrust pastry and the egg whites for the meringue. Weight the egg whites - we add sugar based on their weight (as much sugar as egg whites). Place the egg whites in a clean and dry bowl and place the bowl in the fridge (we'll be making the meringue at the end).
Making the dough by hand: stir the flour with confectioner's sugar and salt. Add the cold diced butter and egg yolks. Rub the butter into the flour mixture with your fingertips until it resembles a pea-sized crumble (crumble can be of different sizes), add cold water, knead quickly until dough forms a smooth ball (be careful not to over mix it). You can add a little more water if the dough is too dry and does not come together.
If you‘re using a stand mixer (my favorite way): add all the ingredients for the pastry except the water into the mixing bowl (flour, salt, sugar, egg yolks, cold diced butter). Mix at the lowest speed using a paddle-shaped attachment, until large lumps are formed (they can be of different sizes, 0.5-1.5 cm / ¼- ½ inch). Add cold water and mix until a smooth dough is formed (be careful not to overmix it). You can add a little more water if the dough is too dry and does not come together.
In the food processor: add all the ingredients (without the water) to the food processor bowl. Pulse 2-3 times until the butter pieces are the size of large peas (they can be of different sizes). Add the cold water and pulse until the dough begins to come together (be careful not to over-mix it). Transfer the dough pieces onto a work surface, and gather them with your hands, forming a dough ball. You can add a little more water if the dough is too dry and does not come together.
All methods: flatten the dough, wrap in plastic foil and put in the fridge for 1 hour.
After putting the dough in the fridge, start making the apple filling.