Preheat the oven to 350 degrees F. Spray a 9x13-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 blend thoroughly.
Add sour cream and flour mixtures alternately to the creamed mixture; spread one half of the batter in the prepared pan and cover with cherries.
Sprinkle one-third of reserved topping over cherries.
Spread the remaining half of the batter on top and sprinkle the remaining two-thirds of the topping evenly over the cake.
Bake 60 to 75 minutes. Cover with foil after 30 minutes if cake is browning too quickly.
Test for doneness by inserting a knife in the center. Serve warm.
