Heat the oven to 350°F Prepare 8" round spring form.
In a separate bowl, mix dry ingredients: flower, salt, baking soda, and baking powder. In another bowl, combine butter, sugar, yokes, vanilla - mix with an electric mixer for 1-2 min or until smooth. Add flour mixture to the butter mixture, and combine. The dough will be soft and smooth, like playdough ;).
Divide the dough into 3 parts, and place one part into freezer. Using your fingers spread the remaining dough in a baking form. I use metal spring form (silicon ones work ok as well).
Prepare the fruit filling: For apple filling, wash and core apples, skin them, and grate them. Spread them over the dough in the baking form - this layer should be about 1-2 inches deep. If you are using apricots, wash and break then into halves. Spread them over the dough so that you have about 2 layers of apricot halves.
Beat the egg whites with confectioner's sugar, until white foam becomes more or less stable. About 5 minute. Pour the foam over the filling.
Get the piece of dough from the freezer, and using the larger grater, grate the frozen dough over the filling. Spread the pieces evenly.
Place in the oven. Bake for about 1 hour. After the pie is ready, let it cool before serving. It tastes best when it is room temperature.