Cream shortening, sugar, and vanilla thoroughly. Add eggs one at a time, beating well after each addition. Sift together flour, baking powder, and baking soda. Add to creamed mixture alternately with sour cream, blending after each addition.
Grease a 10-inch tube pan and line bottom with wax paper. Turn half the batter into pan.
Cream softened butter with brown sugar and cinnamon. Add nuts and toss to make crumbly.
Place half of mixture over first layer. Spread with remaining cake batter and top with remaining nut mixture. Bake at 350 degrees F 45 to 50 minutes, or until cake springs back when lightly touched.
Innkeeper Teresa Jacobson's Note: This is traditionally only baked at Thanksgiving and Christmas. I am not sure how the tradition started, but it is so delicious and moist, I think I may have to break tradition. My two grown boys will eat a whole one!