3/4 c. plus 2 tbsp. sugar
1 c. plus 1 tbsp. all-purpose flour
1/2 tsp. finely grated orange zest
1/4 tsp. cinnamon
1 1/2 lbs. fresh rhubarb, cut into 3/4 inch pieces, or 1 1/2 lbs. frozen rhubarb, thawed (a scant 6 c. of fruit)
1 tsp. baking powder
1/2 tsp. baking soda
1/2 tsp. salt
4 tbsp. chilled unsalted butter, cut into pieces
2/3 c. buttermilk, softly whipped
Cream or ice cream for serving

Preheat oven to 400 degrees. Butter a 1 1/2 to 2 quart oval or rectangular shallow baking dish. Stir together 3/4 cup of sugar, 1 tablespoon of flour, the orange zest and cinnamon. Add the fruit and toss to combine. Spread mixture in the dish and bake for 10 minutes. Meanwhile, in a large bowl, stir the remaining 2 tablespoons sugar and 1 cup flour with the baking powder, baking soda and salt. Add the butter, and using your fingers, rub it into the flour mixture until the size of peas. Make a well in the center and pour in the buttermilk. Stir with a fork until moistened and a soft dough forms.