In a large bowl combine flour, baking powder, confectioner's sugar, egg and a pinch of salt. Shred 1/2 cup 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 cinnamon and brown sugar. 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. Add apples.
In the end shred the remaining dough and spread on the top of the apples.