Peel your potatoes and cut them into halves. Add them to a pot and cover them with water. Boil them over high heat until they're easily pierced with a knife (about 15-20 minutes after they start boiling).
Meanwhile, cut the bacon into small pieces (I like using kitchen shears to make this job easier) and fry it until crispy. Remove the bacon to a paper towel lined plate once it's done.
When the potatoes are about ready, add the butter, cream, and ranch seasoning to a small saucepan. Warm it over medium heat, stirring occasionally so that the ranch seasoning dissolves completely and there's no lumps.
Drain the potatoes thoroughly (I let them sit in a colander in the sink for a few minutes and give them a good shake). This step is important.
Once the potatoes have been drained, add them back to the pot (ensure it's dry). Using a hand-held potato masher, mash the potatoes while gradually adding the cream mixture. Mash until they're just creamy; you don't want to overwork them and make them gummy.
Gently stir/mash in the bacon and scallions (if using) and season with salt & pepper as needed. The ranch seasoning is fairly salty, but I still add some extra salt & pepper for more flavor.