Combine cranberries and sugar in processor. Using on/off turns, coarsely chop cranberries.
Transfer mixture to heavy medium saucepan. Add 1 cup water and orange peel and bring to boil, stirring occasionally. Reduce heat; simmer until mixture is reduced to 2 1/3 cups, stirring occasionally, about 10 minutes.
Cool to room temperature.
Cover; chill overnight or up to 2 days (mixture will thicken).
Brown Sugar Frosting
Using electric mixer, beat cream cheese and butter in large bowl until fluffy.
Add brown sugar; beat until well blended. Add powdered sugar 1/2 cup (scant) at a time, beating well after each addition.
Beat in orange liqueur or orange juice concentrate and vanilla.
Chill until firm enough to spread, about 30 minutes.
Makes about 4 cups.
Cake Instructions and Finished Product
Preheat oven to 350°F.
Butter and flour two 9-inch-diameter cake pans with 2-inch-high sides.
Sift flour, baking powder and salt into medium bowl. Using electric mixer, beat butter in large bowl until creamy. Gradually add sugar; beat until light and fluffy, occasionally scraping down sides of bowl. Add egg yolks 1 at a time, beating well after each addition.
Beat in orange peel, vanilla extract and orange extract.
Whisk milk and yogurt in small bowl to blend.
Add dry ingredients to yolk mixture in 3 additions alternately with milk mixture in 2 additions, beating well after each addition.
Using clean dry beaters, beat egg whites in another large bowl until stiff but not dry. Fold 1/3 of whites into batter, then fold in remaining whites.
Divide batter between pans. Smooth tops. Bake cakes until tester inserted into center comes out clean, about 25-30 minutes.
Cool cakes in pans on rack 15 minutes. Run small knife around sides of pans to loosen cakes. Turn cakes out onto racks and cool completely. (Can be made 1 day ahead. Wrap in plastic and store at room temperature.
Place 1 cake layer, flat side up, on platter. Spread top of cake with 3/4 cup Creamy Brown Sugar Frosting. Spread 1 cup Cranberry Glaze over frosting, leaving 1/2-inch border all around cake.
Top with second cake layer, flat side down; press slightly to adhere. Spread 2 cups frosting over sides of cake
Spoon remaining frosting into pastry bag fitted with medium-size star tip. Pipe decorative border around top and bottom edges of cake. Refrigerate until frosting is firm, about 1 hour.
Spread remaining Cranberry Glaze over top center of cake. Chill until glaze is set. (Can be made 1 day ahead. Cover with cake dome and refrigerate.)
Garnish Top with an orange slice and the bottom with whole cranberries.