Preheat the oven to 400 degrees F. Spray a Bundt pan with nonstick cooking spray. Wrap a 3-foot piece of foil around the center of the pan, scooting it down as best you can.
Cut the tops off the peppers and hollow out the centers to remove the membranes and seeds. Using a small spoon is easiest. Set aside.
Add the garlic to the bowl of a food processor and pulse until finely chopped. Add the feta, cream cheese, oil, pepperoncini and juice. Pulse until it is a smooth mixture. Sprinkle in the parsley and oregano, then pulse a few more times until blended. Spoon the cheese mixture into the hollowed peppers.
Arrange the peppers so that they are standing up nestled side-by-side in a single layer in the prepared Bundt pan. Bake until the cheese mixture is golden, about 30 minutes. Transfer to a serving platter and sprinkle with parsley. Let cool slightly before eating, or serve at room temperature.