In a small cup, dissolve the yeast and sugar in the water. Let stand for a few minutes. Meanwhile, combine the butter, sugar, salt, 1 tbsp lemon peel, and milk in a large mixing bowl. Then add 2-1/2 cups of flour alternately with the yeast mixture. Blend the dough well. Turn the dough out onto a floured board. Knead for about 10 minutes until the dough is smooth and not sticky. Add more flour as necessary. Put the dough into a greased bowl, turning so the top is greased. Let rise in a warm, draft-free place until doubled in bulk, about 1 hour. While the dough is rising, prepare the filling. Combine the poppy seeds, sugar, raisins, milk, and the rest of the lemon peel in the top half of a double boiler. Cook it over hot water until the mixture is of spreading consistency. Stir constantly. It should thicken in about 10 minutes. Remove from heat and cool to room temperature. Punch the dough down, divide in half, and roll each piece into a long rectangle about 1/4 inch thick. Spread the filling on top of each piece, then roll up. Pinch the seams together so the filling can't come out. Place the rolls on a large greased baking sheet and brush with the glaze. Cover the rolls with wax paper laid across water glasses so the paper doesn't touch the dough. Let rise again for 30 minutes. Apply a second coat of glaze. Bake the loaves in a preheated 325 F oven for about an hour. If the top browns too rapidly, cover loosely with aluminum foil. Cool on a wire rack. Makes 2 loaves.