1. In a stand mixer fitted with the paddle attachment, cream together the butter and sugar until light and fluffy. Add the eggs one at a time, scraping the bowl well between each addition. Mix in the vanilla and bananas. In a separate bowl combine the flour, baking soda, and salt. Add 1/3 of the flour mixture to the banana mixture, followed by 1/2 of the yogurt. Scrape the bowl very well between each addition. Mix in another 1/3 of the flour, then the second half of the yogurt, followed by the rest of the flour mixture. Fold in 3/4 cups of the walnuts. Butter and flour a bundt pan or spray with baking spray. Pour batter into pan and bake at 350 for 65-75 minutes, or until a skewer inserted into the center comes out clean. Be sure not to put a baking sheet under the bundt pan, as the hot air needs to circulate through center of the pan.
2. Let cake cool for 10 minutes, then turn out onto a rack and let cool completely. Wrap in plastic and let sit at room temperature overnight, or freeze until ready to use.

For the glaze:

1. combine 1 cup of powdered sugar with 2 tablespoons milk and 1/2 tsp vanilla and whisk until smooth. Pour glaze over the top of the bundt cake and immediately sprinkle on the remaining walnuts.