Preheat oven to 350 degrees. Spray a 13 x 9-inch baking pan with non-stick cooking spray.
To make topping, mix together brown sugar, cinnamon and walnuts in a small bowl; set aside.
Stir together sour cream and baking soda in a small bowl.
In a separate bowl, mix flour and baking powder.
In a medium mixing bowl, cream butter and sugar until fluffy.
Add eggs to creamed mixture, one at a time.
Stir in vanilla and beat blend thoroughly.
Add sour cream and flour mixtures alternately to creamed mixture;
Spread one half of batter in prepared pan and cover with cherries.
Sprinkle one-third of reserved topping over cherries.
Spread remaining half of batter on top and sprinkle remaining two-thirds topping evenly over cake.
Bake 60-75 minutes. Cover with foil after 30 minutes if cake is browning too quickly.
Test for doneness by inserting knife in center.
Serve warm.