Preheat oven to 350°. Line bottom of a greased 9x5-in. loaf pan with parchment; grease parchment., In a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Add eggs, 1 at a time, beating well after each addition. In another bowl, whisk flour, baking powder and salt; add to creamed mixture alternately with cider, beating well after each addition., Transfer to prepared pan. Bake until a toothpick inserted in center comes out clean, 40-50 minutes. Cool in pan 10 minutes before removing to a wire rack to cool completely., In a small bowl, mix glaze ingredients until smooth; spoon over top of cake, allowing it to flow over sides.