1/2 cup unsalted butter, softened
3/4 cup sugar
2 eggs, separated
grated zest of 2 oranges
1-1/2 cups all-purpose flour
1-1/2 tsp baking powder
1/4 tsp baking soda
1/4 tsp salt
1/4 cup fresh orange juice

Orange Glaze
1/2 cup fresh orange juice
1/4 cup sugar

Preheat oven to 350 degrees. Grease a 10-inch Bundt pan. Cream the butter and gradually add the sugar, beating until light. Beat in egg yolks, one at a time, and add orange zest. Sift the flour with baking powder, soda and salt. Add dry ingredients alternately with orange juice to the batter. Beat egg whites until stiff and fold into the batter. Pour batter into the prepared pan. Bake 30 to 35 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes in pan, remove to a rack and drizzle with orange glaze while warm.
Glaze: Combine orange juice and sugar in a small saucepan and simmer gently for 5 minutes, stirring occasionally, until a light syrup forms.