Preheat oven to 350°.
Boil potatoes in salted water until slightly soft.
Remove potatoes and let slightly cool and place on a baking sheet. With a cup or flat hard surface gently smash each potato.
Top each potato with butter, olive oil, garlic, salt, pepper, and parmesan cheese.
Bake in oven for 20-25 minutes until crispy. You can broil for an additional 2 minutes if you like it extra crispy!