Preheat oven to 350F. In small bowl, stir together walnuts,
brown sugar, 3 tbs. flour and the cinnamon.
Coat a 12-cup bundt pan with nonstick cooking spray;
sprinkle 1/3 c. of the walnut mixture into pan.
Set aside remaining walnut mixture.

In a large bowl with an electric mixer at medium speed,
beat granulated sugar and vegetable oil.
Beating well after each addition, one at time add eggs.
Combine remaining flour, baking powder, baking soda, and salt.
Beginning and ending with dry ingredients and
mixing well after each addition, alternately add flour mixture
and buttermilk to batter. Stir in vanilla.

Measure 2 c. of batter; set aside.
Pour remaining batter into prepared pan;
sprinkle remaining walnut mixture over batter.
Pour reserved batter over walnut mixture.
Bake in preheated oven until a wooden pick inserted in center
comes out clean, about 45 min.
Let cool in pan 10 min. on a wire rack; remove from pan.
Let cool completely on wire rack. Makes 16 serving.