Set up your breading station: Line a platter or baking sheet with parchment paper and spread panko breadcrumbs onto a medium plate.
Place crab in a medium bowl. In a separate small bowl, whisk together next 5 ingredients (egg through green onions). Gently fold egg mixture into crab meat until fully combined.
Scoop out ⅓ to ½-cup of the crab mixture and shape into a ½-inch thick crab cake. Gently coat the crab cake in panko breadcrumbs and place on prepared platter or baking sheet. Repeat with remaining mixture.
Heat olive oil and butter in a heavy, large skillet (ideally cast iron) over medium heat until sizzling. Add crab cakes and cook 4-5 minutes, gently press down on the tops with a spatula to flatten them slightly. Gently flip and cook 4-5 minutes more, until golden brown; if they crumble a little on the flip, gently press them back together with your spatula.
Lightly sprinkle with kosher salt to finish (optional). Serve hot with lemon wedges, a sprinkle of fresh parsley or chives (optional) and Remoulade Sauce for dipping.