Buttermilk Coffee Cake

Ingredients
Ingredients for Topping
1/2 cup flour
1/2 cup brown sugar packed
1/4 cup butter softened
1/2 teaspoon cinnamon
Ingredients for Coffee Cake
1/2 cup butter softened
1 cup sugar
1 egg
1 teaspoon vanilla extract
2 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon baking powder
1/4 teaspoon salt
1 cup buttermilk
1 heaping cup Italian plums diced
1 heaping cup blueberries
Directions
Preheat oven to 350 degrees. Butter a 9-inch square pan.
In a bowl, mix topping ingredients together with a fork or pastry cutter until combined. Set aside.
For the cake, beat butter and sugar in a large mixing bowl until fluffy. I do this by hand; a mixer is great. Add the egg and vanilla and beat in.
In a separate bowl, combine flour, baking soda, baking powder and salt.
Mix the dry ingredients into the wet mixture alternately with the buttermilk, stirring just until combined. Batter will be thick.
Gently fold in the fruit, and spread batter into prepared pan. Sprinkle with topping and back to 50 minutes, or until a toothpick inserted in the center comes out clean
The coffee cake is good warm or cold. Cool on a rack for at least 20 minutes before serving.

Page: http://www.pbs.org/food/recipes/buttermilk-coffee-cake/