To make the dough, place the yeast in a small bowl and add the warm milk, sugar, and 1 tablespoon of the flour.

Stir to dissolve, then set mixture in a warm place, lightly covered with a cloth, until it foams, about 20 minutes.

Grease a cookie sheet. In a large bowl, cream the remaining sugar with the butter until smooth.

Gradually add the remaining flour, beating constantly, then add the yeast mixture. Beat with a spoon until mixture forms a large ball.

Turn out the dough onto a floured board. Knead thoroughly for 10 minutes, or until it feels elastic and no longer sticks to your hands.

Transfer dough to a large, greased bowl and cover lightly with a damp cloth. Let rise at room temperature for 1 hour (dough is rather dry, so it will not rise much).

Roll out dough on a floured board into an 8 x 10 inch rectangle. Spread poppyseed filling over the surface, leaving a margin of about 1/2 inch around the edges.

Starting from the side farthest from you, roll dough toward you. When rolled, turn cake over so the seam is on the underside, and tuck the edges of the roll under on each side to prevent the filling from escaping.

Carefully transfer the roll to cookie sheet and cover lightly with a damp kitchen towel. Let rise in a warm place for 1 hour.

Preheat the oven to 400°F.

Uncover cake and place in oven. Bake for 10 minutes, then reduce the heat to 375°F, and bake for 30 minutes more, or until golden brown.

Remove the cake from the oven and let it cool completely before transferring to a wire rack, To make the frosting, sift the confectioners sugar into a bowl.

Make a well in the center and fill with the egg white and lemon juice. Combine ingredients with a wooden spoon until the frosting is absolutely smooth, then spread frosting evenly over the top of the cake, letting it drip down the sides, or drizzle icing in a zigzag manner across top.