Preheat oven to 350 degrees. Butter and flour a nonstick Bundt pan (12-cup capacity), tapping out excess flour; set aside. In a large bowl, whisk together flour, nutmeg, and baking powder; set aside.
In another large bowl, using an electric mixer, beat butter and brown sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Add brandy; beat until combined. With mixer on low, gradually add flour mixture; beat just until combined (do not overmix). Fold in pecans and raisins.
Spoon batter into prepared pan. Bake until cake has pulled away from sides of pan and a toothpick inserted in top comes out clean, 1 1/2 hours. Immediately invert onto a wire rack, and let cool completely.
Set rack with cake over a rimmed baking sheet. In a small bowl, whisk together confectioners sugar and orange juice until smooth. Drizzle cake with glaze.
To store, keep at room temperature, up to 4 days.