Here is the finished product beautifully served on my great grandma's china plates.
You will need puff pastry and mascarpone cheese (or cream cheese). Puff pastry is found in the refrigerator section by the frozen dough and pie crust. I get my mascarpone cheese at Trader Joes or Harmon's - I can never find it at my neighborhood grocery store.
Get out the two sheets of puff pastry and let them sit on your counter for about 35-40 minutes.
In a bowl, mix 1 cup mascarpone (or cream) cheese, 1/2 c. sugar, 1 egg, a handful (or two) of chocolate chips and a dash of vanilla. Beat it all together.
After thawing, unfold the first sheet of puff pastry (it will be tri-folded) and cut it in to four equal squares. Repeat with 2nd sheet of pastry. This will give you 8 large squares.
Put a dollop of the cream cheese mixture in the center of each square.
Quickly beat an egg and brush around the edges of each square with egg wash. Fold the dough over to create a triangle and then press the seams together with a fork to seal. Fold the tip of the triangle up and over just a bit (as seen in next picture).
Place the unbaked croissants on a baking sheet (use parchment or spray with cooking spray). Cut a small slit or two in the top to vent. Use the remaining egg wash and brush on the top of each croissant (don't skip this step or they won't brown and look beautiful).
Bake at 400 degrees for about 18-20 minutes or until perfectly golden brown.