1Preheat oven to 350 degrees F (175 degrees C). Place the tart shells onto a baking sheet lined with parchment paper.
2In a bowl, mash the brown sugar and butter until thoroughly combined, then mix in corn syrup, eggs, and salt to make a smooth mixture. Spoon into the tart shells, filling each one about 3/4 full.
3Bake in the preheated oven until golden brown and the filling is set, 25 to 30 minutes.