Preheat the oven to 350˚. Roll out 1 sheet of pie dough on a lightly floured surface until very thin and about 14 inches in diameter. Cut out 12 rounds with a 2 3/4- to 3-inch cookie cutter. Repeat with the remaining sheet of pie dough. Press the rounds firmly into each cup of a 24-cup mini-muffin pan (preferably nonstick). Lightly prick the bottoms and sides with a fork.
Bake the crusts until lightly browned, 12 to 15 minutes. Let cool slightly.
Meanwhile, cook the bacon in a small skillet over medium heat, turning, until crisp, about 8 minutes. Transfer to paper towels to drain, then finely chop. Whisk the eggs, heavy cream and a pinch each of salt and pepper in a bowl until well combined.
Sprinkle the bacon in the bottom of each crust. Fill with the egg mixture and top with chives. Bake until just set, about 15 minutes (it’s OK if some egg leaks through the pastry). Let cool 10 minutes, then remove from the pan.