Mix dry ingredients into a very large bowl. In another large bowl, whisk together remaining ingredients. Slowly add wet ingredients to dry ingredients just until combined; do not over mix. Cover and let rest for 1 hour or refrigerate overnight.
Heat pancake griddle to manufacturer recommended temperature. (If using a frying pan put on medium heat and turn down to med-low after you pour batter into pan.) Melt butter onto pancake griddle. Add 1/3 cup batter per pancake. Cook pancakes 2-3 minutes or until top bubbles, then ip over. Cook another 2-3 minutes or until cooked through.