Preheat the oven to 450°F. Wash and dry the potatoes. Pierce them in a few places using a fork or a knife. Rub them with olive oil and place them on a baking sheet. Bake in the oven for 45 to 50 minutes until fully baked. Flip them halfway through to ensure even baking.
Take the potatoes out of the oven and let them cool for a few minutes. Cut the potatoes in half and scoop out the insides.
Preheat the oven to 350°F.
Mash the insides using a fork or a hand mixer. Add in the butter, milk, sour cream, garlic powder, salt and pepper. Mix well to combine. Add half of the shredded cheddar and mix well.
Scoop the mixture into the potato skins and top with the remaining cheddar cheese.
Bake in the oven for 20 to 25 minutes until the cheese is melted.
Top with chopped green onions and serve with your favorite main dish.