In a large measuring cup or bowl mix together milk, brown sugar and yeast. Let stand for 10 minutes until foamy. If it doesn't foam, discard and start over.
Add butter, eggs and vanilla to the bowl of stand mixer fitted with a dough hook. Turn on low and add the bloomed yeast mixture, mixing just until combined.
Sift together flour and salt. With mixer on low speed add flour one cup at a time. Add until if forms a shaggy dough. (You may not need all 8 cups.) Add raisins. Turn mixer to medium and knead for 8-10 minutes or until the dough is smooth and elastic. Remove from dough hook, then cover bowl with a damp towel. Allow to rise for 1 hour or until doubled.
Punch down dough, then turn out onto a very lightly floured non-stick surface. Stretch dough into roughly a 12x18 inch rectangle. Brush from end to end with half melted butter.
In a small bowl toss together brown sugar and cinnamon. Sprinkle evenly over butter.
Beginning with the widest edge, roll tightly ending seam side down. Cut in half forming two loaves. You may tuck ends under, if desired.
Place into two buttered 9x5 inch or 10 inch loaf pans. Brush tops with butter, cover loosely with plastic wrap and let rise in a draft free place for 30 minutes.
To bake: Preheat oven to 350°F. Bake bread for 35-40 minutes until the top is golden. (Internal temperature of 190°F) Check at 25 minutes and lay foil on top to prevent over browning, if needed.
Cool in pan for 15 minutes then remove to a cooling rack to cool completely before slicing.
Store in an airtight container at room temperature for up to 3 days.
To Make Three 8x4-inch Loaves: Shape dough into a 12x24-inch rectangle and cut into three even 8-inch portions.