Preheat the oven to 350°F and position a rack in the center of the oven. Grease and flour a bundt pan and set it aside.

Sift the flour, baking powder, baking soda, and salt together onto a piece of parchment paper and set aside.

In a small bowl, whisk together the orange juice, sour cream, buttermilk and brandy and set aside.

In the bowl of a standing electric mixer fitted with the paddle attachment, cream the butter, sugar, orange zest and lemon zest until light and fluffy, scraping down the sides of the bowl as needed. Add the eggs one at a time, mixing well between additions.

With the mixer on low speed, add one-fourth of the flour mixture, mixing until just incorporated, and then add one-third of the orange juice mixture. Repeat with the remaining portions of dry and wet ingredients, alternating until everything is just incorporated. Scrape down the sides of the bowl, making sure that the batter is thoroughly combined. Spoon the batter into the prepared cake pan and smooth the top with the back of a spoon.

Bake until a tester comes out clean and the cake is golden brown, 45 to 50 minutes. Allow the cake to cool on a wire rack for about 5 minutes, then invert cake onto a cooling rack and cool briefly.

Mix the confectioners’ sugar with the Grand Marnier, adding just enough Grand Marnier to achieve a good consistency for drizzling. While the cake is still warm, drizzle the glaze all over the cake and allow the cake to cool before serving.