Heat the oven to 400 degrees and lay the potatoes out on a baking sheet. No need to cut them.
Roast for 35-45 minutes or until tender.
Allow to cool and then chop into 1/2-1" pieces.
Set aside in a large bowl and toss with the salt and pepper.
Heat a skillet over medium heat and add the butter and olive oil.
As soon as the butter melts add the vinegar, garlic, mustard, and sugar.
Whisk and bring to a simmer.
As it begins to cook out a little liquid and thicken slightly, about a minute, add the potatoes and corn and toss to coat.
Remove to a dish, sprinkle with bacon and parsley.