Preheat the oven to 350°F (175°C). Grease a 10-inch Bundt pan well with butter or nonstick baking spray, making sure to coat the ridges and center tube. This will help the cake release easily after baking.

In a large mixing bowl, combine the yellow cake mix and instant vanilla pudding mix. Add the eggs, vegetable oil, orange juice, Galliano liqueur, vodka, and grated orange zest. Beat everything with an electric mixer on medium speed for about 2 minutes.

Scrape down the sides of the bowl as needed and continue mixing until the batter is smooth and evenly combined. Pour the batter into the prepared Bundt pan and spread it evenly with a spatula. Smooth the top gently before placing the pan in the oven.

Bake the cake for 45–50 minutes, or until a toothpick inserted into the thickest part comes out clean or with a few moist crumbs. Remove the cake from the oven and let it cool in the pan for 10–15 minutes before carefully turning it onto a wire rack.

While the cake cools, prepare the glaze. In a small bowl, whisk together the powdered sugar, orange juice, Galliano liqueur, vodka, and orange zest until smooth. Add a little orange juice if the glaze is too thick, or more powdered sugar if it needs to be thicker.

Spoon or brush the glaze over the cake while it is still warm so the flavor soaks in beautifully. Let the cake finish cooling completely and allow the glaze to set for a few minutes before slicing and serving.