Preheat oven to 350 degrees. Butter and flour (or spray with baking spray) a bundt pan. Add pecans to a dry skillet and toast over medium-low heat, about 5-6 minutes, tossing frequently. Watch them carefully so you don't burn them, you'll be able to tell when they are done as they will become very fragrant. In a large bowl, combine flour, brown sugar and salt. Cut in butter, using a pastry blender until mixture resembles coarse crumbs. Scoop out 1/2 cup of mixture and set aside. Add baking powder, baking soda, 1/2 tsp cinnamon, nutmeg and ginger to remaining mixture.
Beat eggs and add to buttermilk in a large measuring cup. Pour into flour mixture, stir until just mixed. Add half the batter to the bundt pan. Combine remaining flour mixture, toasted pecans and remaining cinnamon and sprinkle over batter. Top with remaining batter.
Bake for 40-50 minutes or until a wooden skewer inserted in the center of the cake comes out clean. Cool in pan 10-15 minutes on a wire rack. Cover with cake plate and invert carefully to transfer cake. Cool completely and top with glaze.
In a medium bowl, add powdered sugar, 1/2 the milk or cream, and vanilla. Whisk until smooth. Add remaining milk or cream as necessary to reach desired consistency. You want a syrup-like consistency that can be poured over the cake without running everywhere.