I used leftover carrot pulp from making carrot juice for these, which is much drier than if I had simply grated a carrot. Depending on what route you're going, I would recommend adding in the milk slowly until it's at the right consistency. You don't want it runny like pancake or cake batter, but it shouldn't be so dry you can't stir it at all.
1 1/4 cup whole wheat flour
In a medium to large bowl, mix together the flour, sugar, cinnamon, ginger, baking powder, baking soda and salt. In a separate small bowl, beat together the butter, eggs and 1/4 cup of the milk. Add the wet ingredients to the dry ingredients and mix together, adding more milk if necessary. You don't want it runny like pancake or cake batter, but it shouldn't be so dry you can't stir it at all. Stir in the carrot and nuts.
To freeze the muffins: line a baking sheet with plastic wrap. Use two sheets if necessary to cover it - you don't want to pull it tight or the batter won't fill the muffin cups. Spoon the mix into the muffin cups and freeze for 1 hour. Lift the plastic wrap and frozen muffins out and place in a plastic bag. Freeze again immediately; use within a month.
To cook: Preheat the oven to 350 degrees F. Lightly grease however many muffin cups you're going to be using. Place the frozen or fresh muffin mix into the pan and bake until a toothpick comes out clean when inserted. For fresh mix this will take about 20-25 mins, for frozen it will be 25-35 minutes.