Preheat oven to 400°F (200°C). Line a baking sheet with parchment.
Toss apples with sugar, cinnamon, and lemon juice. Let sit 5 minutes to soften.
Lay one pastry sheet on the pan. Spread apples in a ring, leaving a 1-inch border.
Brush border with beaten egg. Place second pastry sheet on top and seal edges by pressing with a fork.
Cut slits around the ring every 1 inch, twisting each strip outward to show filling.
Brush top with butter and egg wash. Bake 20–25 minutes until golden.
Warm apricot jam and brush on top if desired.