Preheat oven to 325°. Grease and flour a 10-inch tube pan, tapping out excess flour; set aside. Sift together first 3 ingredients. Stir in kosher salt, and set aside.
Cream butter, 2 cups sugar, and zest in a large bowl with an electric mixer on medium speed. Add poppy seeds, and mix well. Add eggs, 1 at a time, beating well after each addition, pausing to scrape down bowl.
Combine buttermilk, 1/2 cup orange juice, and vanilla in a small bowl. Add flour mixture and buttermilk mixture alternately to butter mixture, beginning and ending with flour mixture and beating at low speed after each addition.
Pour batter into prepared pan, and bake at 325° for 55 minutes or until wooden pick inserted in center comes out clean. Let cool on wire rack 20 minutes; remove from pan, and let cool completely on wire rack.
Combine remaining 1/4 cup sugar with remaining 1/4 cup orange juice in a saucepan. Bring to a simmer over medium heat, and cook 5 minutes or until syrupy. Place cake on a serving plate. Brush with warm glaze. Let cool to room temperature before serving. Serve with Citrus Salad, and garnish, if desired.
*Remove eggs from refrigerator, and place in a bowl for 30 minutes.