Scrub the potatoes and prick each several times with a fork. Cook using your preferred method: oven, microwave, Instant Pot, or slow cooker. Allow to cool.

Melt the butter in a stockpot. Whisk in the flour until smooth. Gradually whisk in the milk, whisking constantly. Add the onion powder, salt, and pepper.

Peel the cooled potatoes, leaving a little peel on each. Chop or coarsely crumble by hand.

When the milk mixture reaches a low, gentle boil, remove from the heat. Stir in the potatoes, then return to the stove over the lowest heat setting.

Once the potatoes are heated through, stir in the sour cream, bacon, and cheddar. Heat through, but do not boil.

Garnish each bowl with sliced green onion, if desired.