1/2 cup plus 6 tablespoons butter, softened, divided
1-1/2 teaspoons grated lemon zest
1 teaspoon salt
1/2 teaspoon ground mace
2 large eggs, room temperature
5-1/2 to 6 cups all-purpose flour
3 teaspoons ground cinnamon
In a large bowl, dissolve yeast in warm water. Add the milk, 1/2 cup sugar, 1/2 cup butter, lemon zest, salt, mace, eggs and 2 cups flour; beat well. Stir in enough remaining flour to form a soft dough.
Turn onto a floured surface; knead until smooth and elastic, 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and rise in a warm place until doubled, about 1 hour.
Punch dough down. On a lightly floured surface, roll out dough into a large rectangle, about 1/4 in. thick. Spread with 2 tablespoons butter. Sprinkle with 1/3 cup sugar. Fold in half lengthwise; roll to 1/4-in. thickness. Spread with 2 tablespoons butter; sprinkle with 1/3 cup sugar.
Fold in half widthwise; roll to an 18x10-in. rectangle. Spread with remaining butter. Combine the cinnamon and remaining sugar; sprinkle half over dough to within 1/4 in. of edges. Roll up tightly, starting with a short side; pinch to seal. Cut into 1/2-in. slices.
Place on greased baking sheets (four to six slices per sheet). Cover with waxed paper and flatten with palm of hand. Sprinkle with remaining cinnamon-sugar. Let stand in a warm place for 30 minutes.
Bake at 400° for 12-15 minutes. Immediately remove from pans to wire racks.