These potatoes are guaranteed to be a smashing success!
Meanwhile, place potatoes in large saucepan and cover completely with cold water. Add 1 teaspoon salt and bay leaf.
Bring to boil over high heat. Reduce heat to medium-low and simmer gently until potatoes are soft and paring knife can be inserted very easily into potatoes, 35 to 45 minutes.
Turn off heat. Use ladle to carefully measure ¼ cup cooking water from saucepan into liquid measuring cup and set aside.
Carefully drain potatoes in colander set in sink (ask an adult for help). Discard bay leaf. Return potatoes to empty warm saucepan and let sit, uncovered, until potatoes look dry, about 5 minutes.
While potatoes dry, add melted butter, chives, reserved cooking water, ½ teaspoon salt, and pepper to softened cream cheese and whisk until smooth.
Use back of wooden spoon to smash potatoes in saucepan just enough to break skins. Don’t work potatoes too much (finished dish should be chunky).
Butter can be melted in a small saucepan on the stove (use medium-low heat), but we think the microwave is easier. Here’s how to do it: