Wash the potatoes well under running water. Peel them carefully using a potato peeler. Cut them into evenly sized chunks. This helps them cook evenly and become soft when boiling.

Place the potato pieces into a large pot. Add enough water to fully cover them. Add one teaspoon salt to the water. Bring to a boil and cook until potatoes become very tender.

After about 15 minutes, test the potatoes with a fork. If the fork slides easily through them, they are ready. Drain the potatoes using a colander and remove all excess water.

Place the drained potatoes into a large mixing bowl. Use a potato masher to mash them slowly. Mash until most lumps disappear but do not overmix or the potatoes may become sticky.

Add butter while the potatoes are still hot. Pour in warm milk slowly while mixing. The heat helps melt the butter and creates a creamy and smooth mashed potato texture.

Add sour cream, black pepper, garlic powder, and salt. Mix everything gently using a spoon or hand mixer. Continue mixing until the potatoes look fluffy, smooth and creamy.

Taste the mashed potatoes before serving. Add extra salt or pepper if needed. Mix gently again so the seasoning spreads evenly throughout the potatoes.

Transfer the mashed potatoes to a serving bowl. Add chopped parsley on top if desired. Serve warm with your favorite main dishes for a comforting and satisfying meal.