Blueberry-Rhubarb Upside-Down Cake

Last fall I signed up for a weekly vegetable box from my local CSA (Community Supported Agriculture). I did it for a number of reasons.

• Participation in a CSA supports local farmers, take that Monsanto. 
• I know that our food is local, this great for our environment. 
• Being local the our food is probably picked the day before it gets to us, meaning it will last much longer in our refrigerator. 
• The majority if not all of our veggies and fruit are organically grown.

All good reasons, but one of my favorite reasons is that the box contains what the box contains. There is no picking or choosing. This means we get stuff in the box that we never buy, sometimes it's something I've never even heard of.  This may be daunting to some, but I love it.  It's been good for our family; we have greatly expanded our repertoire of veggies. Which brings me to to today's recipe made with rhubarb.

Rhubarb is not new to me, I've seen it in the grocery store for years but never once purchased it.  This week it arrived in my veggie box. First of all is it a fruit or a vegetable?  Well I went to Wikipedia to get the answer and found that it seems to be both.  Well not really, it's a vegetable.  What is funny is that in 1947, a New York court deemed it a fruit since that is the way it is used in America.  Whatever, who am I to argue, I am using it as a fruit.

I was going to make rhubarb pie, but I have to admit I was afraid we might not like it, that's when I came across a recipe in Eating Well magazine for Strawberry-Rhubarb Upside-Down Cake.  I thought that sounded perfect, well almost, the hubby was never going to eating something made with strawberries and rhubarb, so I swapped out the strawberries for blueberries.  The results were awesome, this is a super easy homemade cake that takes very little effort.

The recipe below was taken directly from Eating Well with a few small changes, such as the blueberries.  I also used a different pan.  The whole inversion process of the upside-down cake is very intimidating to me, as it should be, I've mangled more than one of these in my time.  I used a springform pan which allowed me to safely remove the sides of the pan and the get the top (bottom) of the cake firmly on the plate before flipping it over. Another note, since I used a springfrom pan, some liquid seeped out of the bottom while it was in the oven, it didn't effect the results, but I would highly recommend putting a large baking sheet lined with foil on the rack below your pan to catch the drippings.

Blueberry-Rhubarb Upside-Down Cake
(Adapted from Eating Well's Strawberry-Rhubarb Upside-Down Cake)

1 cup sliced fresh rhubarb
3/4 cup orange juice, preferably fresh-squeezed, divided
3 tablespoons granulated sugar
2 1/2 cups blueberries
3 large eggs
2/3 cup extra-virgin olive oil
3/4 cup packed light brown sugar
1 tablespoon freshly grated orange zest
2 teaspoons vanilla extract
1 1/2 cups flour
2 teaspoons baking powder
1/2 teaspoon salt

Preheat oven to 350°F. Generously spray a springform cake pan with cooking oil. Combine rhubarb, 1/4 cup orange juice and granulated sugar in a medium bowl and let stand, mixing occasionally, for 20 minutes. Add blueberries; stir to combine. Spread the fruit mixture in the prepared pan.

Whisk eggs, oil, brown sugar, orange zest, vanilla and the remaining 1/2 cup orange juice in a large bowl. Whisk flour, baking powder and salt in a medium bowl. Gradually stir the dry ingredients into the wet ingredients. Do not overmix. Spoon the cake batter on top of the fruit mixture. the batter will seem thin, but it is fine.

Bake until a toothpick inserted in the center of the cake layer comes out dry, 40 to 50 minutes.

Run a knife around the outside of the pan and shake it a bit to loosen the bottom. Remove the sides of the pan and invert the cake onto a serving plate and remove the bottom. Let the cake cool to room temperature before serving, about 2 hours.