Peel the russet potatoes and cut them into even 1-inch chunks for consistent cooking.

Fill a large pot with cold water, add a generous pinch of salt, and bring to a rolling boil.

Add the potato chunks to the boiling water and cook for 12 to 15 minutes until tender when pierced with a fork.

Meanwhile, cook the chopped bacon in a skillet over medium heat until crispy and golden, about 8 minutes; transfer to a paper towel and reserve 2 tablespoons of bacon fat in the skillet.

Drain the potatoes in a colander and let them steam for 1 minute to release excess moisture.

Return the potatoes to a large bowl and mash with a potato ricer or masher until mostly smooth with a few small lumps remaining.

Stir in the unsalted butter, warm milk, and sour cream until the potatoes reach your desired creaminess.

Fold in the shredded cheddar cheese, cooked bacon, sliced green onions, and garlic powder, then season with salt and black pepper to taste.