1 box yellow cake mix (super moist)
1/2 c. butter
1 c. biscuit mix
1 pt. sour cream
3 eggs
1 1/2 c. brown sugar
1 c. walnuts

In small bowl mix together biscuit mix, brown sugar, butter, and walnuts until crumbly. In large bowl, blend eggs, sour cream, and cake mix. Batter will be lumpy. Add 1/2 cup cold water. Spread 1/2 batter in greased 9 x 13 inch pan and sprinkle 1/2 streudel mix (from small bowl) layer over batter in pan. Layer other half of cake mix mixture and sprinkle with remaining half of streudel mix. Bake 40 to 45 minutes at 350 degrees.

Drizzle with powdered sugar frosting, if desired.