1. Preheat the oven to 300°. Generously butter and flour a standard 12-cup, 10-inch Bundt pan, preferably nonstick.
2. Make the Cake: In the bowl of a standing electric mixer fitted with the paddle, beat the butter with the sugar and salt at medium speed until light and fluffy, about 5 minutes. Add the eggs 1 at a time, beating well between additions. At low speed, beat in the flour and cream in 3 alternating batches, scraping down the side of the bowl once or twice. Beat in the vanilla and the lemon zest, lemon juice, orange zest and orange juice.
3. Scrape the batter into the prepared pan and bake for about 1 hour and 45 minutes, until the top is golden and lightly cracked and a toothpick inserted in the center of the cake comes out with a few moist crumbs attached. Let the cake cool in the pan on a rack for 15 minutes, then turn the cake out onto the rack and let it cool completely.
4. Make the Glaze: In a medium bowl, whisk all of the ingredients together until smooth. Using a skewer, poke deep holes all over the top of the cake. Brush the glaze all over the cake in several layers until thickly glazed. Drizzle any remaining glaze on top and let it set before serving.