• Preheat oven to 350°F. Prepare a 12-cup Bundt pan with non-stick baking spray. (or butter and flour)
• In a medium-size bowl whisk together the flour, baking powder, salt, and baking soda.
• Cream the granulated sugar and butter in a large bowl with an electric mixer on medium speed until light and fluffy, 4 to 5 minutes. 
• Add eggs, 1 at a time, beating well after each addition.
• Alternately add flour mixture and buttermilk to butter mixture in 4 additions, beginning and ending with flour, beating until blended after each addition. 
• Blend in the vanilla extract, lemon extract, lemon zest, and orange zest.
• Pour the batter into the prepared pan; smooth top.
• Bake in preheated oven until a wooden pick inserted in the center comes out clean, 45 to 50 minutes. Cool in pan on a wire rack 20 minutes; remove from pan, and cool completely on the rack.

Prepare the Lemon-Orange Glaze:

• Whisk together powdered sugar, fresh lemon and orange juices in a bowl until smooth. Drizzle the glaze over the cake allowing it to drip down sides. Let stand until set, about 20 minutes. Garnish with thin lemon or orange slices, if desired.