In a large bowl sprinkle yeast over 1/4 cup warm water; let stand about 5 mins.

Heat milk and butter to 110@. Add milk mixture, sugar and salt to softened yeast. Lightly beat eggs to blend. Spoon 1 tbsp of the eggs into a small bowl, cover and chill. Add remaining eggs and vanilla to yeast mixture; stir to blend. Add 2 1/2 cups flour, nutmeg and cinnamon; stir to moisten, then beat with a mixer on high speed til dough is stretchy, 6 to 8 mins. Stir in 1 cup flour to moisten.

Knead dough. If using a dough hook, beat on high speed tildough pulls cleanly from bowl and no longer feels sticky, about 5 mins, If dough is still sticky, beat in more flour, 1 tbsp at a time. If kneading by hand, scrape dough onto a well floured board. Knead til dough is smooth, elastic and no longer sticky, about 12 mins; add flour as needed to prevent sticking. Return dough to bowl.

Cover bowl airtight and let dough rise in a warm, draft-free place til it doubles, about 1 1/2 hours. Punch dough down. Knead on a lightly floured board to expel air. Form into a 7" round and set on a buttered 12 x 15" baking sheet. Cover lightly with plastic wrap and let rise in warm place til puffy, about 40 mins.

Uncover dough and brush gently with reserved beaten egg. Sprinkle loaf with sesame seed. With a sharp, floured knife, make a slash about 1/2" deep across the middle of the loaf. Bake loaf in a 350@ oven til richly browned, 35 to 40 mins. Serve warm or cool. If making ahead, wrap cool loaf airtight and let stand at room temp up to 1 day; freeze to store longer. If desired, cut a slit in the bread and insert a day of the dead decoration such as a miniature skull or skeleton.