Preheat the oven to 375 degrees F. Line 2 baking pans with parchment paper.
Divide the egg white from the egg yolk and place in a small bowl; set aside.
Beat the egg yolk, cream cheese, sugar, lemon juice and vanilla in a medium bowl with an electric mixer on medium-high speed until smooth.
Lay out the 2 sheets of puff pastry and roll them with a rolling pin just enough to get the creases out of the puff pastry, then cut each into 4 squares.
Fold the corners of the squares over by about 1 inch to make octagon shapes.
Brush the tops of the pastry with the egg wash generously.
Scoop or spoon the cream cheese mixture evenly into the center of each (about 2 tablespoons per danish). Do not spread the cream cheese.
If you want to add bits of fruit or fruit filling, place on top of the cream cheese dollops.
Bake 15 minutes and rotate pans around, then place back in oven until puffed and golden brown for another 15 minutes.
Cool slightly and drizzle some easy glaze on top before serving.