Generously grease the inside of a 10-inch bundt pan with butter or shortening and dust it with flour. Tap out any excess flour.
Combine the butter and sugar in a large bowl and cream until light and fluffy. Add the eggs, one at a time, beating well after each addition. Beat in the vanilla.
In another bowl, whisk the flour, baking powder, salt and baking soda together.
Mix 1/3 of the flour mixture into the butter and sugar mixture. Add half of the buttermilk and mix to combine, followed by another 1/3 of the flour mixture. Finish by beating in the remaining buttermilk, and finally the last of the flour. Use a spatula to make sure the mixture is completely mixed in. The batter will be thick.
Pour the batter into the prepared bundt pan. Bake until a tester inserted in the center comes out clean, about 60 minutes.
Let the cake cool for 15 minutes, then remove from the pan to cool completely on a wire rack.
Once the cake is cool, place it on a serving plate.
Place the butter, brown sugar and cream in a saucepan and place over medium heat. Bring the mixture to a boil, stirring constantly. Remove from the heat. Whisk in the powdered sugar. Let the icing sit for 10-15 minutes, whisk one more time, then pour the icing over the cake. Let the icing set before serving.
Notes
Adapted from Taste of Home Annual Recipes 2008Nutrition information provided as an estimate only. Various brands and products can change the counts. Any nutritional information should only be used as a general guideline.