Beat the eggs and milk until light and foamy, about 3 minutes at high speed of a stand or hand mixer. Stir in the butter or vegetable oil. Whisk the dry ingredients together to evenly distribute the salt, baking powder and sweetener. Gently and quickly mix into the egg and milk mixture. Let the batter rest for at least 15 minutes, while the griddle is heating; it will thicken slightly. Heat a heavy frying pan over medium heat, or set an electric griddle to 375°F. Lightly grease frying pan or griddle. The pan or griddle is ready if a drop of water will skitter across the surface, evaporating immediately. Drop 1/4 cupfuls of batter onto the lightly greased griddle. Bake on one side until the edges look dry, and bubbles begin to form and break, about 2 minutes; then turn the pancakes and cook the other side until golden brown, about 1 1/2 to 2 minutes. Turn over only once. Serve immediately with maple syrup.