Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a 9-inch fluted tube pan, such as Bundt.
Sift together flour, baking powder, ground ginger, cinnamon, and salt. Set aside.
In a large bowl, cream together butter and brown sugar until light and fluffy. Beat in eggs one at a time, then stir in grated ginger root and vanilla. Beat in flour mixture alternately with milk, mixing just until incorporated. Pour batter into the prepared pan.
Bake in the preheated oven for 45 to 50 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool in pan for 10 minutes, then turn out onto a serving plate. Dust lightly with confectioners' sugar before serving.