In a large bowl, combine flour, chocolate chips, brown sugar, baking powder, baking soda and salt and cinnamon.
In a large glass measuring cup or another bowl, whisk together buttermilk, pumpkin, eggs and melted butter. Pour mixture over dry ingredients and stir using a rubber spatula just until moist.
Lightly coat a griddle or nonstick skillet with cold butter.
Working in batches, scoop 1/4 cup batter for each pancake. Cook until bubbles appear on top and underside is nicely browned, about 2 minutes. Flip and cook pancakes on the other side, about 1-2 minutes longer.