For Muffins whisk all dry ingredients together in a large bowl.
In a separate bowl whisk together the rest of the ingredients. Combine the wet ingredients into the dry ingredients until just moistened.
Lightly spray a 12 cup muffin tin with cooking spray and divide the batter into the 12 cups.
Bake on the middle rack of oven until muffins are light brown and a toothpick inserted in the center comes out clean. (About 20 minutes)Let muffins cool, until cool enough to handle.
In a medium-size bowl whisk together the sugar and cinnamon. Melt the butter in a separate pan or bowl. Using a pastry brush coat the muffins generously with melted butter, and then roll them in the sugar until thoroughly coated. Place the muffins on a wire rack to cool.