Pour milk into small saucepan. Scrape in seeds from vanilla bean; add bean. Bring to simmer. Remove from heat; cover and let steep 20 minutes. If necessary, rewarm milk until instant-read thermometer inserted into mixture registers between 105°F and 115°F before continuing.
Blend sugar and lemon peel in processor.
Mix 1 1/2 cups flour and yeast in bowl of heavy-duty mixer fitted with paddle attachment.
Discard vanilla bean from milk and add warm milk to bowl; beat to blend. Let stand until slightly puffed, about 15 minutes.
Add 3 cups flour, eggs, and brandy to yeast mixture; beat on medium speed until smooth and slightly firm dough forms, adding more flour by tablespoonfuls if dough is sticky or adding water by tablespoonfuls if dough is dry, about 6 minutes.
Add sugar-lemon peel mixture and salt. Beat on medium speed 5 minutes.
Add butter and beat until absorbed and dough is smooth and soft, about 5 minutes longer.
Cover bowl tightly with plastic wrap. Let dough rise in warm draft-free area until doubled in volume, about 2 hours.
Generously butter 12-cup Bundt pan.
Turn dough out onto lightly floured surface; knead gently into ball. Using fingers, make hole in center of dough, creating doughnut shape. Transfer to prepared pan, pushing hole in dough over center tube in pan. Cover pan with plastic wrap; refrigerate overnight (dough will rise to top of pan).
Remove dough from refrigerator. Let dough rise in warm draft-free area until dough no longer springs back when gently pressed with fingers, about 1 hour 30 minutes (dough will rise above pan by 1 to 1 1/2 inches).
Meanwhile, position rack in lowest third of oven and preheat to 350°F
Bake bread until well browned on top, about 20 minutes.
Wrap sheet of foil loosely over top and sides of pan to prevent overbrowning. Continue to bake bread until deep brown on top and tester inserted near center comes out clean, rotating pan occasionally for even baking, about 40 minutes longer. Immediately invert bread onto rack.
Stir preserves in small saucepan over medium heat until melted. Brush preserves all over warm bread. Cool completely, at least 3 hours.
Sift 1 1/3 cups powdered sugar into small bowl. Add lemon juice and whisk to blend. Add more powdered sugar by tablespoonfuls if glaze is too thin to adhere to bread.
Drizzle glaze over cool bread and let stand until glaze sets, about 1 hour. (Can be made 1 day ahead. Wrap loosely in foil and store at room temperature.).