Heat oven to 200°. Peel potatoes and shred coarsely in a food processor or on a box grater. Put in a kitchen towel and wring out as much liquid as possible.
In a bowl, mix potatoes and remaining latke ingredients with 1/4 cup vegetable oil.
Heat 1 1/2 tbsp. remaining oil in a large, heavy nonstick frying pan over medium-high heat. Spoon in scant 1/4 cupfuls of latke batter to form 5 pancakes; flatten to a thickness of 1/2 in. Cook until dry-looking around edges and browned underneath, about 3 minutes. Flip and cook other side until browned, about 2 minutes. Transfer to a baking sheet and keep warm in oven. Cook remaining latkes the same way, adding more oil as needed.
For each plate, spoon about 1 tbsp. crème fraîche onto each side and smear toward center. Top with 2 or 3 latkes and some green onions. Sprinkle with espelette pepper and sea salt.
*Find smoky, fruity gochugaru (not to be confused with the Korean chile paste called gochujang) at Asian markets and online. Find mild Spanish espelette pepper at specialty shops and online.