Preheat oven to 400 degrees and line a baking sheet with aluminum foil. Then place a folded oven-safe cooling rack (or cookie rack) inside the baking sheet.
Arrange the bacon in a single layer on top of the rack.
Bake for 23 to 28 minutes (check after 18 minutes for thin bacon or if your oven runs hot, or cook longer for thicker bacon), or until desired crispiness.
Pat the tops with paper towels to remove excess oil to help them get crispy. Then, allow to set for a few minutes to firm up before serving.
Notes
The bacon will shrink as it cooks, so the pieces can touch and be close together, but do not overlap so they get nice and crispy.
Bacon can go from not-quite-done to burned very quickly. When it is close to being done, be sure to check on it every few minutes.
I don't recommend using a different quantity of bacon. However, if you cook less bacon, you will need to reduce the cooking time and keep a close eye on it so it doesn't burn.
Be sure to use a cooling rack and not a broiler pan! The broiler pan doesn't allow enough airflow to get the bacon crispy.