Preheat oven to 350 F. Shred zucchini on paper towels, then fold up and gently press to remove excess moisture.
Shred carrots and do the same with paper towels. Melt butter and set aside.
In a bowl beat egg, add milk, sugar, and melted butter. In another bowl mix together flour, baking powder and salt. Then incorporate the dry into the wet ingredients.
Fold in shredded zucchini and carrot. Fill sprayed or muffin liner filled muffin cups 3/4 of the way full.
Bake for 18-20 minutes (for regular size) or about 10-11 minutes for mini, or until top springs back when touched gently in the center.
If adding cream cheese frosting do so once cooled, and sprinkle crushed nuts on top too if desired.