Preparation
Preheat the oven to 350°F (175°C). Grease and flour a 10-inch tube pan.
In a large bowl, cream the butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Beat in the vanilla extract.
In a separate bowl, mix together the flour, baking powder, baking soda, and salt. Add to the creamed mixture alternately with buttermilk, beating well after each addition.
Pour the batter into the prepared tube pan. Bake for 55-70 minutes, or until a toothpick inserted in the center comes out clean.
Cool the cake in the pan for 10 minutes. Run a knife around the edges and the center tube of the pan, then invert the cake onto a wire rack over waxed paper.
For the butter sauce, combine the sugar, butter, and water in a small saucepan. Cook over medium heat until the butter is melted and the sugar is dissolved. Remove from heat and stir in the vanilla extract.
Poke holes in the top of the hot cake and pour 1/4 cup of the sauce over the cake. Let the cake stand until the sauce is absorbed.
Enjoy your delicious butter cake with vanilla butter sauce!