1. In the bowl of a stand mixer, pour milk followed by eggs, vanilla, sugar, agave nectar, and salt. Place flour, spices, and orange zest on top.
2. Combine yeast with lukewarm water and add paste to bowl.
3. Using a dough hook, mix until dough is elastic and smooth, about 5-7 minutes on medium speed.
4. Gradually add pieces of butter to dough allowing it to be fully incorporated before adding next amount.
5. Add raisins and mix until just combined. Cover bowl with plastic food wrap and set in a warm place (top of refrigerator or in oven which was turned on for a few minutes) and allow dough to rise until doubled in volume, about 60-80 minutes.
6. Remove dough from bowl, this will make dough collapse which is normal and required. Cut dough into 24 equal pieces and shape round. Place in a buttered pan about 1-inch apart.
7. Brush with beaten egg and cover with plastic food wrap. Return to a warm place and allow to rise for about 30-45 minutes or until buns have gained about 60% in volume. Meanwhile preheat oven to 350°F.
8. Remove plastic and brush rolls very gently to avoid deflating them. Place in oven and bake until light golden for about 18-20 minutes.
9. Allow to cool on pan.