For the dough, heat milk in a small saucepan until lukewarm, no more then 105 degrees. Sprinkle yeast on surface and whisk in. Set aside.

By machine with paddle attachment, beat together sugar, salt, and butter until soft and light. Beat in egg and yolk until smooth. Scrape bowl and beater and beat in vanilla and spices. Beat in half the flour, then the yeast mixture, then remaining flour, scraping bowl and beater between each addition. Continue beating on low speed about 2 minutes, until dough is elastic.

Scrape dough into a lightly buttered bowl and cover with plastic wrap. Allow to ferment at room temperature until almost double in bulk, about 1 hour.

While dough is fermenting, prepare crumb topping. Beat almond paste and egg white with paddle until smooth. Beat in sugars, then butter until smooth and free of lumps. Beat in cinnamon, then flour, scraping bowl and beater occasionally. By hand rub mixture to 1/4-to 1/2-inch crumbs. Set aside covered.

To form buns, scrape dough to a floured surface and press to deflate. Press dough to an 10 by 16-inch rectangle. Cut the dough into twenty 2 by 4-inch rectangles.

Preheat oven to 375 degrees and set rack in the middle level. Butter and line with parchment paper a 12 by 18-inch jelly roll pan. Arrange the rectangles of dough 5 across the 12-inch side of the pan and 4 down the 18-inch length, spacing them evenly. Brush tops of buns with water and sprinkle with 3/4 of the crumb topping. Cover the buns with plastic wrap and allow to rise until almost double. Sprinkle with the remaining crumb topping after the buns have risen.

Bake the buns about 30 minutes, until they are firm and the crumb topping has colored. Slide the buns from the pan to a rack to cool. When cooled, dust lightly with confectioners' sugar.