Sour Cream Coffee Cake

from cooking light: i haven't made it yet but plan on it soon!

3/4 cup ol fashioned rolled oats, divided
1 c flour
1/4 c whole what flour
1 t baking powder
1/2 t baking soda
1/4 t salt
1/2 c sugar
1/2 c brown sugar
1/3 c butter
2 large eggs
1 t vanilla
1 (8oz) carton light sour cream
2 T finely chopped walnuts, toasted
1/2 t cinnamon
1 T chilled butter, cut into small pieces

1. preheat oven to 350.

2. spread oats on single layer on a baking sheet. bake at 350 for 6 minutes or until oats are barely fragrant and light brown.

3. coat 9 inch pan with cooking spray; set aside.

4. reserve 1/4 c oats; set aside. place reamining oats in a food processor; process 4 seconds or until finely ground. lightly spoon flours into dry measuring cups; level with a knife. combine processed oats, flours, baking powder, baking soda, and salt; stir with a whisk.

5. place granulated sugar, 1/4 c brown sugar and 1/3 c butter in a large bowl. beat with a mixer at medium speed for 3 minutes. add eggs, 1 at a time, beating well after each addition; beat in vanilla. add flour mixture to sugar mixture alternately with sour cream, beginning and ending with flour mix (batter will be slightly lumpy because of oats). spoon batter into prepared pan, spread evenly.
6. combine remaining 1/4 c oats, remaining 1/4 brown sugar, nuts, and cinnamon in a bowl. cut in 1 T butter with pastry blender. sprinkle top of batter evenly with nut mixture. bake at 350 for 38 minutes or until a wooden pick comes out clean. cool cake 10 minutes.