Preheat the oven to 400°F (204°C). Wash 4 medium-sized baking potatoes and brush off any visible dirt. Pat them dry and place them on a baking sheet.
Poke a few holes in the potatoes with a fork, and then drizzle 1 teaspoon of olive oil on each potato and rub them with your hands until they are well coated.
Bake at 400°F for 60-75 minutes, until they can be easily pierced with a fork and give slightly when pressed, indicating that the middle is tender.
Remove from the oven and allow to cool for about 5-10 minutes, then slice them in half lengthwise with a sharp knife. Scoop out the insides with a spoon, leaving about 1/4 inch of the potato skin attached as a shell that can support itself..
Place the potato flesh in a large bowl along with vegan butter, plant milk, sour cream, salt, and garlic. Use a potato masher to blend the mixture until it's creamy.
Add chives (or green onions), 1 cup of vegan cheese, and bacon bits, and stir to combine.
Fill the potato skins with the potato mixture and sprinkle the tops with the remaining cheese. Reduce the oven temperature to 350°F (176 °C) and bake for 20 minutes, or until the tops are golden brown.
Sprinkle with additional bacon bits and chives and serve hot.
Notes
Be sure to leave some of the potato attached to the skin so it retains its structure and holds its shape.
The mashed potato mixture will be slightly wetter than regular mashed potatoes, but that is okay, as moisture will escape when you bake them for the second time.