1. Combine sour cream, powdered sugar, brown sugar and cinnamon. Divide mixture in half; add peanut butter to one half and set aside both mixtures. 2. In mixing bowl combine sugar, shortening, egg, milk, flour, salt and baking powder. Blend well using low speed of electric mixer or beat well with a wooden spoon or whisk. 3. Spread half of egg batter in a 9 x 9-inch pan that has been greased and floured on bottom only. Top with peanut butter mixture, followed with remaining egg batter. Spread sour cream mixture over top then sprinkle with nuts. 4. Bake in preheated 350-degree oven for 35-40 minutes or until cake springs back when touched lightly in center.
