The night before you want to make pancakes mix together the oatmeal, whole wheat (or buckwheat) flour, and buttermilk. If using the flax seed, add this now too. Stir together, then cover.
In the morning, add the sucanat (or organic sugar), eggs, salt, and baking powder.
The oatmeal mix will be kind of dry from sitting overnight. You'll need to use a spoon to break up the large chunks and smooth out the batter. This will take a bit of time. However, in my experience, adding more milk for soaking turns into an extra-thick mass that doesn't rise properly. So, this is ultimately a better solution.
Add your milk, and keep stirring it and breaking up chunks until you get a fairly uniform batter. There will still be some small chunks, and that's okay.
Heat a large frying pan on medium-high heat, and melt some butter.
Pour small spoonfuls of batter into the pan. I did mine in about 2" circles.
When the bubbles pop and stay open, and the edges are golden brown (about 3 - 4 minutes), flip them.
Cook them for 2 - 3 minutes, then remove them from the pan.