Preheat the oven to 450 degrees.
Add the potatoes to a pot full of salted lukewarm water. Bring to a boil for 15-20 minutes or until soft enough to pierce with a fork.
Remove the potatoes and lay on a paper towel lined plate to drain.
Put potatoes on the tray, leave 1-2 inches between each one. Drizzle olive oil over all the potatoes and rub each one to make sure the olive oil coats the whole potato evenly. Use a masher to lightly smash each potato.
Use a brush to coat each potato with olive oil. Get in all the cracks and crevices! Sprinkle salt, pepper, garlic powder, & rosemary over each potato.
Put the tray into the oven and cook for 15 minutes. Remove and add crumbled pieces of goat cheese to each potato and then put it back into the oven for 5-10 more minutes. When the potatoes are browned and crispy, they're done! Garnish with green onions.