Preheat oven to 425 degrees.
If your potatoes are large, cut them in half. You want to work with small to medium sized yukon gold potatoes.
Bring a large pot of salted water to a boil.
Add potatoes to the water (no need to peel them).
Once the water re-reaches a low boil, set a timer for 14 minutes.
Drain the potatoes.
Oil the bottom of two sheet pans.
Take the potatoes and using the bottom of a mug, smash the potatoes down onto the sheet pan.
Season with garlic powder, onion powder, salt, pepper and dried parsley.
Top the potatoes with 8 tbsp diced butter (4 tbsp per sheet pan)
Bake on bottom rack for 30 minutes. If you don't have enough room to fit both sheet pans on the bottom rack, place one on top and one on bottom and rotate them halfway through cooking.
Check the potatoes and rearrange the potatoes if some are more done than others. Usually the perimeter of the pan is a hot spot and browns quicker than the middle. Put middle potatoes on the outside and outside potatoes in the middle. Put back in the oven for 10-15 more minutes.
Remove from the oven and serve warm.