The answer is yes, you can. Instead of freezing the entire muffin batter, fill the muffin cups or paper liners with batter in the muffin pan and place the entire pan in the freezer. Make sure you set the pan flat so the muffin batter doesn't spill and hold their shape. Freeze until rock-hard, about 6 - 8 hours. Then carefully lift each of the filled paper liners out of the pan and transfer them to a freezer-safe container. Or wrap each one tightly in double layers of plastic wrap and place them in a freezer bag. Store in the freezer for up to 3 months.