In a small bowl, stir together 2 cups sour cream and 2 tsp baking soda. Set aside.
In a medium mixing bowl, cream butter and sugar until fluffy. Add eggs to the creamed mixture, one at a time. Stir in vanilla and 1 Tbsp baking powder and beat blend thoroughly.
Add sour cream mixture and 4 cups flour alternatively to the creamed mixture until a thick batter forms.
In your prepared 9"x13" dish, add ½ batter and spread across evenly.
Add sliced strawberries in an even layer, then sprinkle with ⅓ of the reserved cinnamon mixture.
Spread the remaining batter on top and then sprinkle the remaining ⅔ topping evenly over the 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.