In a medium bowl place the flour, cinnamon, chopped nuts, and sugar and use a fork to incorporate.
Drizzle in the melted butter and use the fork (or your fingers to blend ingredients together). Set aside while making the muffins.
Preheat oven to 350F. Grease 10 muffin cavities with soft butter and sprinkle with flour.
In a medium bowl, sift together the flour, cinnamon and baking powder. Mix to incorporate.
In a large bowl, whisk together the sugar, molasses, and eggs until light and frothy. About 30 seconds.
Drizzle in the oil and water and whisk to combine.
Fold in the shredded carrots.
Fold in the flour mix.
Fill the greased muffin tin all the way to the top and sprinkle with streusel.
Bake for 20-24 minutes turning the pan halfway the baking time.