In a med. bowl combine dark brown sugar, pecans & cinnamon. Take out 5 tblsp of this mixture and set aside in small bowl.
Add 1/2 C raisins to the medium bowl of brown sugar, pecans & cinnamon mixture. Set aside.
In a separate bowl mix together flour, baking soda and salt. Set aside.
In Kitchen Aid mixer blend margarine and sugar. Add eggs one at a time to this mix.
Stir flour mix into butter mixture ALTERNATING with the sour cream. Stir until smooth.
Grease and flour a 10" tube pan.
Layer 1/3 batter (2 cups), 1/3 nuts mixture w/raisins, 1/3 batter, 1/3 nuts w/raisins, 1/3 batter, 1/3 nuts w/raisins mix.
Sprinkle remaining 5 tblsp brown sugar, nuts, cinn. mix on top.
Bake 350 degrees It says to bake 1 hour & 10 min but check it at 50-55min. Knife should come out clean.
Cool completely before trying to remove from pan.