Rhubarb crisp

Rhubarb crisp 
* see below for gluten-free options

I hardly ever measure for stuff like this; these quantities are guidelines.

2 pounds rhubarb, sliced into 3/4-inch pieces 
1 cup sugar
3/4 cup flour*

Crisp topping:
2/3 cup margarine or butter, softened (not melted!)
3/4 cup brown sugar (or more, to taste)
1 cup flour*
1 cup whole oats
1 1/2 teaspoons cinnamon

Heat oven to 375 degrees. Lightly grease 9x13 pan.

Add cut rhubarb to pan, mix with cup of sugar. Let sit for a few minutes to draw out juices, then sprinkle flour and stir well. 

Meanwhile, use pastry blender or your hands to mix crisp topping into pea-sized crumbs. Crumble over rhubarb mixture and bake in 375 degree oven until top is lightly browned and rhubarb is bubbling, about 30 minutes. Serve warm or cold. Ice cream or yogurt are a delicious topping. 

*Gluten-free options: Replace flour in rhubarb mixture with 3 Tbsp. cornstarch. Replace flour in crisp topping with a cup of oats that you have processed fine in the blender or food processor. Add this to the other cup of whole oats with the rest of the ingredients.