Preheat oven to 325°F.
Butter and flour a 12-cup angel food cake pan with removable bottom or you may use a 12 cup *bundt cake pan.
Using electric mixer, beat butter in large bowl until fluffy. Gradually beat in sugar, then lime zest and salt. Bet in eggs 1 at a time. Add flour and lemon powder in 3 additions, beating just until blended each time. Transfer batter to prepared pan.
Bake cake until a golden color and tester inserted near center comes out clean, about 1 hour. Cut around center tube and pan sides of angel food cake pan to loosen cake. Remove pan sides.
Cool cake completely.
*If using a bundt cake pan, cool cake in pan for 5 minutes. Turn cake out on rack; cool completely.
Whisk together powdered sugar, lemon powder and lime juice until smooth.
Transfer cake to a plate, then drizzle glaze over cooled cake and let stand until glaze is set, about 20 minutes.
Cooks Note: Cake (without glaze) can be made 1 day ahead and kept, wrapped tightly in plastic wrap, at room temperature. This recipe can be made with all organic ingredients.