Rhubarb Buttermilk Cake

My Rhubarb Buttermilk Cake
Adapted from Mollie Katzen
  • 1 1/2 cups chopped rhubarb (small bite-sized)
  • 3 tbsp sugar
  • 2/3 cup butter at room temperature (I normally use unsalted, but used salted here as it was all I had)
  • 2/3 cup sugar
  • 2 large eggs at room temperature
  • 1 tsp pure vanilla extract
  • 1 1/2 cups unbleached all-purpose flour
  • 1/2 tsp salt
  • 1 tsp baking powder
  • 1/8 tsp baking soda
  • 1/2 cup buttermilk
For the Topping:
  • 1/3 cup butter, at room temperature
  • 1/2 cup unbleached all-purpose flour
  • 1/2 cup sugar (white)
  • 1 tsp ground cinnamon
Spray an 8 inch square pan with non-stick spray and preheat oven to 350 degrees.  Place the chopped rhubarb in a small bowl and toss with 3 tbsp sugar, set aside.  In large mixing bowl, cream butter and (second amount of) sugar and beat in eggs one at a time, then add vanilla (you could do this part with an electric mixer if you want to, but do the rest by hand so the batter does not get over-mixed).  In another bowl, mix all remaining dry ingredients together and add to the butter/sugar/egg mixture alternately with the buttermilk, mixing just until combined.  Fold in the sugared rhubarb and scrape the batter into prepared pan, smoothing top somewhat.
Mix the topping ingredients together by hand until big crumbles form and scatter them evenly over the batter.  Bake cake at 350 for 45 minutes or until done in the center.