Beat the butter with the sugar, flour, eggs, and 200 ml (approximately 1 cup) of orange juice. Add the baking powder and the zest of one orange in an electric mixer. Bake in a greased springform pan and bake for about 40 minutes in a preheated oven at 180°C (approximately 350°F). Let cool and remove from the pan and let cool on a wire rack.
Meanwhile, cut the peel from the second orange and cut the peel into thin strips. Mix the pomegranate and orange liqueur. Add the zest and let soak for 30 minutes.
Cut the orange into sections. Peel the oranges with a sharp knife, carefully remove the white pith. Cut the oranges int slices. Mix 50 ml (approximately 1/4 cup) of cold orange juice with the cornstarch. Boil the remaining orange juice with the cinnamon stick. Stir the juice with the cornstarch mixer and simmer for 3-4 minutes while stirring. Fold in the orange segments.
Spread the orange sauce on the cake. Arrange the zest on top of the oranges. Serve while still warm.