Lemon lime Pound Cake (with Lemon lime Glaze)

Preheat the oven to 325 degrees. Butter and flour a 9 x 5 x 3-inch loaf pan. In a large mixer bowl, cream the butter until smooth, about 1 minute. Gradually add 1-1/2 cups of the sugar and beat until light and fluffy, 4 to 5 minutes. Add the eggs, one at a time, beating well after each addition, beat in the grated lemon and lime zest. Sift together the flour, salt and baking powder onto a sheet of waxed paper. Gradually add the dry ingredients to the butter mixture in 4 to 5 additions, beating on low speed until just blended after each addition. Spoon the batter into the prepared pan. Bake the cake for 1 hour and 15 minutes, or until a cake tester inserted into the center comes out clean and the edges of the cake begin to pull away from the sides of the pan. Leave the cake in the pan and allow it to cool on a rack for 5 minutes. Meanwhile, in a small nonreactive saucepan, combine the 1/2 cup sugar, the lemon juice and the lime juice. Cook over moderate heat, stirring until the sugar dissolves, 1 to 2 minutes. Do not boil. Remove the citrus glaze from the heat. Invert the pan to unmold the cake. Set it on a rack over a sheet of waxed paper. While the cake is still warm, brush all over with the hot citrus glaze. Let cool completely. Wrap in plastic wrap anf then overwrap with aluminum foil. Let the cake stand in a cool place for at least 1 day before slicing. The cake will improve overnight and will keep, tightly wrapped, for up to 1 week.