Preheat the oven to 350°F (175°C).
Grease a 9x13 inch baking pan with vegetable oil or non-stick spray.
In a large mixing bowl, combine 1 cup orange juice, ½ cup vegetable oil, and 3 eggs. Whisk until smooth.
Gradually add 1 box lemon cake mix to the wet ingredients, stirring gently until just combined. Do not overmix; some lumps are fine.
Fold in 1 tablespoon poppy seeds and the zest of 1 orange and 1 lemon.
Pour the batter into the prepared pan and spread evenly.
Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
Cool the cake in the pan for 10 minutes, then transfer to a cooling rack to cool completely.
Make the glaze by whisking together 2 cups sifted powdered sugar and 2-3 tablespoons orange juice until smooth and drizzly.
Once the cake is completely cooled, drizzle the glaze over the top and garnish with additional orange and lemon zest.