Put warm milk into a medium bowl; stir in 1 T. sugar. Sprinkle with the yeast; let stand 5 minutes or until the surface is frothy. Stir gently to moisten any dry yeast particles remaining on the top.
Sift 6 2/3 cups flour salt, and remaining sugar into a large bowl.
Add the vanilla and the grated lemon peel to the yeast mixture and stir.
Pour the yeast mixture into the flour mixture, combining to make a semi firm dough.
On a floured surface, knead dough until smooth.(use your stand mixer with the bread hook if you have one)
Place dough in a bowl and cover with a warm moist cloth or towel and let rise in a warm place for 1 hour. (I heat my oven on 200 degrees for about 2 min and turn it off)
Mix raisins,almonds and candied peel in a medium bowl; sprinkle with rum. Cover and let steep.
Work butter and remaining flour together; knead into risen dough. Cover and let stand in a warm place for 15 minutes.
Work fruit and rum mixture quickly into dough. Cover and let stand in a warm place for 15 minutes.
Grease baking sheets or cover with parchment paper.
Divide dough into 3 portions.
On a floured surface, gently roll each piece into a 12-inch oval which is thinner in the middle than at the edges. Fold dough over lenghtwise, making a 6 inch length. This gives the typical stollen shape.
Place dough on baking sheet. Repeat with remaining 2 pieces of dough.
Cover and let stand in a warm place 20 minutes, until increased in size.
Preheat oven to 350 degrees F.
Bake stollen 30-35 minutes or until a rich golden brown.
To make Topping: melt butter. Brush melted butter over the hot stollen. Sift powdered suggar generously over stollen.