FOR THE CAKE
Preheat over at 350 degrees for 30 minutes prior to baking.
Prepare 13x9 inch baking by lightly coating with cooking spray. (Note: you can also bake this in 2, 9-inch cake pans. That way you’ll have one for sharing.
In a large mixing bowl, stir together flour, sugar, soda and salt.
Add the sliced rhubarb and lightly toss to coat rhubarb with flour.
In a separate bowl, combine the egg, oil, Greek yogurt and vanilla. Stir into the flour mixture until combined.
Pour this mixture into the 9x13 baking pan and set aside.
In a small bowl, combine topping ingredients by using a pastry blender or pulsing briefly in a food processor. Sprinkle topping mixture over top of cake, so cake is covered evenly.
Bake for 35 minutes or until top springs back when touched.
FOR THE CARAMELIZED RHUBARB
In a sauté pan, melt the butter, then add the brown sugar and stir until well combined and bubbling.
Stir in the rhubarb and continue cooking, stirring gently (rhubarb has a lot of liquid and will fall apart easily so be really careful not to overdo it. I use a nonstick pan and just pretty much shake the rhubarb back and forth as opposed to stirring it around).
Cook rhubarb only until softened. Remove from heat and top slices of the cake with a big spoonful. If you don’t use it all, try it on ice cream. It will make you very happy.