In a large bowl combine flour, baking powder, confectioner's sugar, egg and a pinch of salt. Shred cold butter and combine with flour. Knead the dough by hand or in the mixer with dough hook attachment.
Make a ball, cover with foil and place in the fridge for 30 minutes.
In the meantime, in a large pan melt 4 Tbsp. butter, add apples and cook on low-medium heat for 10 minutes. When apples will be soft add brown sugar and cinnamon. Cook for another 5 minutes.
Preheat oven to 350 F. Prepare 13 x 9 baking pan with parchment paper.
Remove the dough from the fridge and cut about 3/4 dough. Leave the rest for the top.
Spread 3/4 dough on the bottom of the baking pan nicely by hand. Add apples.
In the end shred the remaining dough and spread on the top of the apples.
Bake for about 1 hour.