Preheat oven to 350 and grease a bundt pan. Cream together the butter through the vanilla. Combine the dry ingredients in a separate bowl and add to the creamed mixture. Fold in sour cream and mix well. Combine brown sugar, nuts and cinnamon to make streusel. Pour one-third of batter into pan and top with one-third of streusel. Repeat two more times. Bake for 50-60 minutes. When still warm, turn cake from pan and glaze with: 1/3 cup butter, melted and slightly burnt; 2 cups powdered sugar; 1 1/2 teaspoon vanilla; and 2-4 tablespoons hot water. Combine the ingredients in saucepan over low heat and stir until lumps disappear.
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