Combine oats and buttermilk and stir to ensure oats are coated. Put in the fridge overnight covered. In the morning, add remaining ingredients and mix well. I usually use a hand mixer for a few seconds to get everything well-blended but have also blended by hand. Cook over a fairly low heat on a pre-heated, greased griddle or cast iron pan. They take longer to cook than regular pancakes so you want to make sure they cook slowly over med-low heat. The key is not to cook too hot, just let them brown slowly over the low heat. I use a cast-iron pan and it works very well. Serve warm with maple syrup, jam, or a fruit compote.