To prepare a gooey butter cake, combine butter, sugar, eggs, vanilla, and vanilla extract. Beat with an electric mixer until light and fluffy, about 5 minutes. Add flour, baking powder, salt and baking soda and beat until combined. Fold in buttermilk. Pour batter into prepared pan and bake in 375 degree oven for 35 to 40 minutes or until toothpick inserted in center comes out clean. Let cake cool in pan for 10 minutes before removing to wire rack to cool completely.