Grease the inside of a 9-inch cake pan with butter, sprinkle the remaining sugar to coat the butter and lay the sliced oranges on the bottom of the pan.
Next, pour the cake batter on top of the layer of oranges and bake at 350ºF for 40 minutes or until a toothpick comes out clean when inserted into the middle.
Allow the cake to cool while preparing the glaze. To make the glaze, whisk the orange juice and powdered sugar together in a small bowl.
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Then, invert the cake on to a platter. Gently lift the pan up, and the cake should slide. Drizzle the orange upside-down cake with the glaze and cool before serving.