Cut potatoes into 1-inch chunks and place them in a large bowl. Add the olive oil, salt, pepper, and garlic powder, then toss everything together until the potatoes are evenly coated. Make sure each piece is well-oiled—this helps create that golden, crispy exterior. While you're coating the potatoes, preheat your oven to 425°F.

Spread the coated potatoes on a baking sheet in a single layer with the flat sides down—this creates maximum contact with the hot pan for better browning. Dot the potatoes with small pieces of butter distributed across the pan. Roast at 425°F for 25-30 minutes until the bottoms are golden brown and crispy. I find that using salted butter like Kerrygold adds a richer, more complex flavor than unsalted butter, which really elevates the final crust.

Flip the potatoes so the browned sides face up and the uncooked sides make contact with the hot pan. Return to the oven for another 15-20 minutes until the second side is golden and the potatoes are tender when pierced with a fork. Remove from the oven, taste for seasoning, and add a sprinkle of salt if needed. Garnish with fresh parsley and serve immediately while still warm and crispy.