1. Preheat the oven to 200°C.
2. Cook the bacon in a sauté pan until crispy; let cool and then crumble.
3. Scrub the potatoes, then place them on baking sheets. Rub the potatoes with the rapeseed oil and bake until tender, 45 minutes to 1 hour. Remove the potatoes and lower the oven temperature to 180°C.
4. Slice the butter into pats and transfer to a large mixing bowl. Add the bacon and sour cream. With a sharp knife, cut each potato in half lengthwise and scrape out the insides into the mixing bowl. Tear up 3 of the skins and throw them in. Smash the potatoes with a potato masher. Add the cheese, milk, seasoned salt, green onions and some salt and pepper and mix together well.
5. Butter a baking dish, and then spoon the mixture into the dish, top with more grated cheese and bake until warmed through, 25 to 30 minutes.