In a large mixing bowl, add the butter and melt until soft (about 30 seconds). Shred 2-3 zucchini squash into a bowl until you have 1 ½ cups of shredded squash. Add these shreds to the butter. Add the sour cream, white sugar and eggs and mix until smooth. You can use an electric mixer or a whisk.
Add baking powder, baking soda, salt, cinnamon, allspice and flour. Mix until combined.
Heat oven to 350 degrees. Place muffin wrappers into a muffin tin. Scoop about ¼ cup of batter into each muffin wrapper. Sprinkle on the top some cinnamon sugar. Bake at 350 for 15-18 minutes, or until tender in the center but not runny. Serve warm.