Preheat oven to 400°. Line a baking sheet with parchment paper or silicone baking mat.
Unfold the puff pastry. Cut the dough into 4 equal squares then cut each square diagonally, resulting in 8 triangles.
Working with 1 triangle at a time, position it so the wide end is facing you and the point is away from you, like a 90 degree triangle. Add roughly 1 teaspoon apple butter to the cente
Roll the dough up from the wide end to the point, pinching in the dough so the apple butter doesn't ooze out. Transfer to the baking sheet and curl the ends towards the center to make a crescent shape.
Repeat with the remaining triangles.
In a small bowl, combine the sugar and cinnamon. Brush each croissant with egg, then sprinkle with cinnamon sugar.
Bake 12-15 minutes or until puffed and golden. Serve warm or at room temperature.
Croissants are best served the day they are made.