Combine the flour, 1 cup sugar, baking powder, salt, buttermilk, beaten egg, vanilla and oil and stir just until moistened.
In a small bowl, combine cinnamon and remaining sugar.
Pour half of the batter into pan and sprinkle with with 1/2 the raspberries, 1/2 the nuts and 1 cup of the cinnamon-sugar.
Spread with remaining batter and sprinkle with remaining raspberries, nuts and cinnamon-sugar.
Using a knife, cut through the batter to swirl a few times.
Bake for 60-75 minutes or until a toothpick inserted near the center comes out clean.
Allow to cool for 10 minutes in the pan before removing to wire rack. Cool completely.