Rhubarb Buttermilk Coffee Cake

I remember my mom making this coffee cake years ago.  We were recently gifted some rhubarb and I decided to make this cake.  It is just as light and flavourful as I remember!

Ingredients:

2 cups diced fresh or frozen rhubarb

1/4 cup plus 2/3 cup sugar; divided

1/2 cup butter, softened

2 eggs

1 1/2 tsp. vanilla

1 1/2 cup all-purpose flour

1 tsp. baking powder

1/2 tsp. salt

1/8 tsp. baking soda

3/4 cup buttermilk

Directions:

1.  Combine rhubarb and 1/4 cup sugar; set aside.

2.  Cream butter and remaining sugar until light and fluffy.

3.  Add eggs, one at a time.  

4.  Stir in vanilla.

5.  Combine flour, baking powder, salt and baking soda; add to creamed mixture alternately with buttermilk.

6.  Fold in rhubarb.

7.  Pour in a greased 9" square pan.

8.  Combine 2 tbsp. brown sugar and 1/2 tsp. ground cinnamon; sprinkle over batter.

9.  Bake at 350F for 25-30 minutes.