Peel and core the apple. Slice the apple into small pieces and place them in a small bowl. Add in the cinnamon and toss the apples until they are coated.
Cut the Brie into 18 pieces - they should be just about .3 ounces each, or a generous teaspoon's worth, but don't be too worried if every piece isn't exactly the same.
Preheat oven to 400° F. Have ready a nonstick mini muffin pan (or 2 if need be, this recipe makes 18 puffs.)
Assemble the puffs:
Have the ingredients ready: the diced apples, the Brie pieces, and the fig jam, before you cut the puff pastry. Lightly flour a work surface.
Unfold one sheet of the puff pastry on the lightly floured work surface. Roll it out just a bit with a rolling pin to make the dough a little thinner. Slice the puff pastry with a sharp knife of pizza cutter into 9 squares.
Fit the puff pastry squares into the muffin pan, 1 square per well, fitting the dough down into the well with the edges hanging out. Repeat these steps with the second sheet of puff pastry so that you have 18 pastry shells ready. (If at any point the dough is getting too warm and difficult to work with, pop it into the freezer for 10 minutes to firm up.)
Place a piece of Brie into a pastry shell, topped with about 1 teaspoon of diced apple and then 1 teaspoon of fig preserves. Repeat this to fill the remaining pastry shells with Brie, apple, and fig.
On each pastry shell fold in two opposite corners of dough and then the other two. Pinch the dough together firmly at the top to seal it shut. Repeat these steps on all of the filled puffs.
Bake:
Mix the egg white with a teaspoon of water in a small dish. Brush the tops of the puffs with the egg white mixture. Bake the puffs for 15-20 minutes until they are puffed and browned.
Remove the pan from the oven and place the pan on a cooling rack. Allow the puffs to cool in the pan for 10 minutes before taking them out.
Place them on a decorative platter and serve them while they're warm.