Blackberry Sour Cream Coffee Cake

1/2 cup unsalted butter, softened
1 cup sugar
2 eggs
1 cup sour cream
2 cups flour
1 tsp salt
1 tsp baking powder
1 tsp baking soda
1 tsp vanilla
1 cup blackberries

Cream together butter and sugar until fluffy. Add eggs one at a time, beat well. Add sour cream and mix until smooth. Sift together dry igredietns and add. Blend vanilla thoroughly. Fold in berries.

Pour 1/2 batter in greased and floured 8x8 square.

Sprinkle topping: (half of it)
1/4 c unsalted butter
1/2 c. brown sugar
1/2 tsp cinnamon

Pour remainder of batter and sprinkle rest of topping.

Cook 350 for 40 min to 1 hour or until done