Cook bacon in heavy large skillet over medium heat until brown and crisp. Transfer bacon to paper towels and drain. Crumble bacon finely. Mix butter, sage and bacon in medium bowl. Season lightly with salt and pepper. Can be made 2 days ahead. Cover and chill. If using return to room temperature.
Pat turkey dry. Season cavity with salt and pepper. Place leeks, fennel, 8 sage sprigs and bay leaves in cavity. Loose the skin of the Turkey breast and spread 1/3 cup sage butter over breast meat. Put Turkey on roasting rack. Rub 2 tablespoons sage butter over outside of turkey. Set aside 1/3 cup butter for gravy; save the rest for basting. Can be made 1 day ahead if you return it to room temp before continue. Cover, chill.
Position rack in bottom third of oven and preheat to 350°F.
Pour 1/3 cup broth over turkey. Roast turkey until thermometer inserted into thickest part of inner thigh registers 180°F.
NOTE be sure to baste every 30 minutes with 1/3 cup broth and occasionally brushing with sage butter. Transfer turkey to platter; tent with foil. Let stand 30 minutes.
Remove rack from pan. Pour off juices and skim then return to pan. Set pan over 2 burners set on high heat. Add 2 cups broth. Boil until liquid is reduced to 2 cups, scraping up browned bits, about 10 minutes. Whisk in reserved 1/3 cup sage butter. Season with pepper. Transfer gravy to bowl.
Uncover platter. Garnish with sage and parsley.
Note Time is guess because conditions vary. Use a thermometer.