Truck-Stop Buttermilk Pancakes

In a large bowl, whisk together the eggs, milk, butter and buttermilk. Combine the flour, baking powder, baking soda and sugar; stir into the wet ingredients just until blended. Adjust the thickness of the batter to your liking by adding more flour or buttermilk if necessary.
Heat a large skillet over medium heat, and coat with cooking spray. Pour 1/4 cupfuls of batter onto the skillet, and cook until bubbles appear on the surface. Flip with a spatula, and cook until browned on the other side. Continue with remaining batter.