Thaw puff pastry on the countertop for about an hour or so, until it’s pliable.
Preheat oven to 400℉.
Once the pastry is thawed enough to work with, unfold one sheet and cut into 4 even squares. I found that this was really easily accomplished with a pizza cutter. With your hands, gently stretch out each square to make it about 1-½ times the size, being careful not to rip the pastry.
Put a few slices of apple and a few slices of pear in the middle of each puff pastry square.
Sprinkle a little cinnamon and nutmeg over top (no measurements here, just to taste), then 1 tablespoon light brown sugar, 1 tablespoon granulated sugar, and 1 tablespoon salted butter.
Next, fold up the pastry around the fruit. Fold up two opposite sides to the middle (or almost the middle), then the other two opposite sides to seal the fruit inside the pastry.
In a small bowl, beat 1 egg and a splash of water. Brush egg wash over the top of each pie, then sprinkle with coarse sugar.
Place on a parchment-lined baking sheet and bake for about 25 minutes, or until pastry begins browning. Due to stretching out the pastry earlier, they won’t puff up very much. This is to be expected.
Serve mini apple pear pies warm, with homemade whipped cream or ice cream. Yum!
You can also make these the day before, keep them in the fridge overnight, then reheat in the oven at 250℉ for about 20 minutes.