Beat butter and sugar a medium speed in mixer until light and fluffy
Add eggs, one at a time, beating just until blended after each addition.
Combine flour and next 4 ingredients, add to butter mixture alternately with sour cream, beginning and ending with the flour mixture.
Beat at low speed just until blended after each addition.
Spread batter in a greased and floured 13x9 inch pan.
Stir together the brown sugar, pecans and cinnamon; sprinkle over batter.
Cover pan with plastic wrap tightly, and chill 8 to 18 hours.
Preheatoven to 350º
Bake coffee cake 35 minutes or until toothpick in center comes out clean.
Remove from oven.
Serve warm or at room temperature.