Preheat the oven to 400º F and line a baking sheet with parchment paper.

Cut a thin slice from both ends of the potatoes. Using a melon baller, hollow out a cavity on one end of each potato.

Place the prepared potatoes in a mixing bowl and drizzle with the melted butter. Season with salt and pepper and toss to coat. Transfer the potatoes to the baking sheet; stand upright on the end without the cavity. Leave room on the sheet for the bacon. Spread the diced bacon in a single layer on the sheet. Roast until the potatoes are tender when pierced with a knife and the bacon is crisp, 18 to 20 minutes. Remove from the oven; cool for 10 minutes.

Combine the sour cream and the dill in a small bowl. Put the mixture into a pastry bag and pipe into the cavity of each potato. Sprinkle the potatoes with bacon and serve.