Directions

Line a rimmed baking sheet with a silicone baking mat or parchment paper.
Cook bacon in a medium nonstick skillet over medium heat until most of the fat is rendered and bacon is starting to crisp. Transfer bacon to a sieve set over a small bowl; reserve drippings.
Return bacon, 1 Tbsp. drippings, sugar, and sesame seeds to same skillet. Cook over medium heat, stirring frequently, until sugar turns the color of milk chocolate, about 5 minutes. Transfer mixture to prepared baking sheet and use a spatula to spread out evenly; let cool. Break brittle into shards. DO AHEAD: Can be made 1 day ahead. Store airtight at room temperature.
Preheat oven to 400°. Place sweet potatoes on a foil-lined baking sheet. Roast until tender, 45–55 minutes. Let sit until cool enough to handle.
Slice potatoes in half lengthwise. Working over a large bowl, scoop out flesh from 8 halves, leaving a 1/2-inch-thick layer inside skins. Place potato halves on same foil-lined baking sheet. Scoop flesh from remaining 4 halves; discard skins. Mash flesh with a whisk; add eggs, butter, miso, and ginger and stir until mixture is smooth. Spoon or pipe filling into reserved skins. DO AHEAD: Can be made 6 hours ahead. Cover and chill.
Bake potatoes until the tops are lightly puffed and golden brown, 30–35 minutes (potatoes will take longer if they’ve been chilled). Top potatoes with bacon-sesame brittle and scallions.