In a large microwavable cup (at least 2 cups), heat the milk in the microwave for about 45 seconds to 1 minute, until it is warm. Add in the sugar and stir until it is dissolved. Add in the yeast and give it a quick stir. Set aside.
In a large bowl, mix together all the dry ingredients. Make a well in the middle of the bowl and add in the milk and yeast mixture.
Mix together until it forms a rough dough, then add in the butter one cube at a time while kneading the dough with your hands. Continue kneading for about 5 minutes, until you have a smooth dough. If the dough is too sticky, add in 1 tablespoon of flour at a time to make a soft smooth dough.
Add in the grated carrots and continue kneading for about 3 more minutes until the carrots are well dispersed. If the dough is becomes too sticky, add in 1 tablespoon of flour at a time to make a soft smooth dough. Place the dough back in the bowl and cover with a tea towel. Leave it in a warm place for about 1 hour, until it almost doubles in size.
In the meantime, in a small bowl, mix together the brown sugar, cinnamon, pecans or walnuts, and raisins. Set aside.
When the dough is ready, split the dough in half. On a lightly floured surface, roll out half of the dough to form a rectangle about 20cm x 30cm (12-inch x 8-inch) and 1/4 inch thick. Spread on half of the butter, then evenly sprinkle on half of the brown sugar mixture. Beginning on the long side, slowly roll up the dough to form a log. Set aside. Repeat with the remaining dough.
Cut the dough into 5 cm (2-inch) pieces. Place in a greased baking pan, leaving about 2cm (3/4-inch) between each piece. Cover with a tea towel and leave it in a warm place for about 45 minutes, until it almost doubles in size.
In the meantime, make the frosting. In a medium bowl, add in all the ingredients and mix with a spatula until the sugar is combined. Using an electric hand beater on high speed, beat everything together until smooth. Cover and place in the refrigerator until ready to be used.
When the dough is almost ready, preheat oven to 175°C/350°F. Bake in the oven for about 20-25 minutes, until golden brown.
Remove from oven and let it cool slightly before spreading on the cream cheese frosting.