Grease and flour a 9 x 5 inch loaf pan. Preheat oven at 350°F (180°C).
In a medium bowl, sift together all-purpose flour, baking powder, baking soda, and cinnamon. Set aside.
In a large bowl cream butter and brown sugar until light and fluffy, about 2 minutes. Beat in egg.
Add flour mixture, marmalade, and milk. Beat on low speed until just combined.
Pour batter into prepared pan. Bake for 50 minutes or until a wooden pick inserted in the center comes out clean.
Cool on wire rack for 10 minutes. Remove from pan and allow cake to cool completely.
Mix powdered sugar with 1 tablespoon cool water in a small bowl. Drizzle over the top of the cake.
Sprinkle orange rind decoratively on the top.