Grease side and bottom of 2 (10 inch) tube pans.

Prepare Topping; set aside.

In a shallow, medium bowl, dissolve yeast in warm water. Add 1 Tbsp sugar and 1/2 cup flour; stir to combine. Cover; let stand in a warm place 5 to 10 minutes until foamy.

Heat milk and butter or margarine in a small saucepan until melted. Let stand until mixture cools to warm.

In a large bowl, beat eggs, egg yolks and remaining 1 cup sugar until pale and frothy.

Add cooled milk mixture, salt and yeast mixture. Beat unil smooth.

Gradually beat in 4 1/2 cups flour.

Stir in enough remaining flour to make a soft dough. Turn out dough on a lightly floured surface.

Knead dough into a soft, smooth dough. Divide dough in 1/2. Arrange 1 part dough in each greased pan. Cover with a damp cloth; let rise in a warm place, free from drafts, until doubled in bulk, about 2 hours.

Preheat oven to 350 F.

Lightly beat 2 egg whites in a small bowl until foamy. Brush beaten egg whites on top of dough.

Evenly sprinkle Topping over dough. Bake 50 to 55 minutes or until a wooden pick inserted in centre comes out clean.

Cool cakes in pans 3 to 4 minutes on racks. Turn out of pans; cool completely on racks.

Frost with Powdered sugar Icing if desired. Makes two (10 inch) cakes.

Topping: In a small bowl, combine sugar, flour, and cinnamon. Using a pastry blender or 2 knives, cut in butter or margarine until mixture resembles coarse crumbs.

Powdered sugar Icing: 2 egg whites 1 1/2 cups sifted powdered sugar 1/2 tsp lemon juice. In a medium bowl, beat egg whites until frothy. Gradually add powdered sugar, beating constantly. Beat 10 minutes or until glossy. Add lemon juice; beat 2 minutes or until icing stands up in soft peaks. Makes about 1 1/4 cup icing.