In a large bowl, whisk together 1½ cups all-purpose flour (spooned and leveled), 2 tablespoons cane sugar, 1 tablespoon baking powder, and ½ teaspoon sea salt.
In a medium bowl, whisk 1¼ cups milk, 1 large egg, and 3 tablespoons melted (and slightly cooled) unsalted butter, or whisk in a neutral oil if using that option.
Pour the wet ingredients into the dry ingredients and gently fold with a spatula until just combined; a few small lumps are fine. Do not overmix. If the batter is very thick, add additional milk 1 tablespoon at a time until the batter is thick but pourable.
Heat a nonstick skillet or griddle over medium-low heat until warm (a few drops of water should sizzle gently). Lightly brush the pan with extra butter or oil.
Use a ⅓-cup scoop to pour batter onto the hot skillet, leaving space between pancakes.
Cook until bubbles form on the surface and the edges look set, about 1 to 2 minutes, then flip and cook the other side until golden brown and cooked through, about 1 to 2 minutes more. Lower the heat if the outsides are browning too quickly before the centers are cooked.
Transfer cooked pancakes to a plate and keep warm while you cook the remaining batter. Serve with maple syrup.