Preheat the oven to 400°F.
Cook 7 strips of bacon until crispy, then finely crumble and set aside.
Finely chop 1 medium apple.
In a bowl, combine the chopped apple, 1 1/2 cups shredded cheddar cheese, the bacon, and 1 whisked egg until evenly mixed.
Roll 1 sheet of puff pastry into a rectangle on a lightly floured surface. Spread the filling evenly over the pastry, leaving a small border on one edge.
Roll the pastry tightly into a log, seam side down, and chill for at least 20 minutes to make slicing easier.
Slice into 3/4 inch rounds and place on a parchment-lined baking sheet. Bake for 18 to 20 minutes, until puffed and golden.
