Rhubarb and raspberry upside-down cake

At the beginning of rhubarb season this year, I had this most brilliant thought to make a rhubarb upside-down cake. I discussed the idea with my mom, but I didn't really look into it much. We decided that rhubarb is too watery when it cooks, and that it wouldn't work well, unless maybe we precooked it... We figured it probably wasn't a good idea. I'm more of a tarte tatin kind of girl anyways, and I had honestly never eaten an upside-down cake of any kind before. So, I just pushed the idea aside.

Then, an article on rhubarb upside-down cake, followed by a recipe, appeared in the New York Times.

Well then.

Maybe my idea wasn't so stupid after all. If it's New York Times worthy, it's got to be good!

So, I tried out the recipe.

The thing that bothered me the most about the article in the New York Times was the photo of the rhubarb upside-down cake with the pinkish-purple streaks of syrup. Apparently the color came about because the rhubarb wasn't peeled. But, I've never peeled my rhubarb before, and never do any of my rhubarb desserts end up that color. The rhubarb in my parents garden, and the rhubarb that is sold in the Montreal markets is not that pink. Our variety is more green then pink, and once cooked, it's really kind of a yellow-ish green, certainly not the vibrant pink pictured in the New York Times. I wonder where they get their rhubarb from because I'd love to get my hands on some and bake with it to see the difference. My usual solution to the rhubarb color issue is to pop in a few raspberries to brighten up the color, so that's what I did here. Plus, I love both raspberry and rhubarb desserts, so I was happy to combine them into one. Of course, if you are a flavor-purist (no judgement here, I really do understand if you are), just go with rhubarb only for this recipe. Just don't expect a fantastic pink dessert if your rhubarb is anything like ours.

I tweaked the original recipe a fair amount. I used yoghurt (2.5% fat) instead of sour cream. I omitted the lemon zest and lemon juice and I upped the amount of yoghurt instead (people are so obsessed with adding citrus to their baking, and sometimes, I really don't understand why!). I added some ground ginger to the dry ingredients, though I have to say, the ginger flavor seemed completely absent in the final cake. The flavor of the cake was so great as is that I really didn't miss that ginger flavor that I had been aiming for with my tweaks. The tang of the yoghurt really came through in the batter and the cake, and that tang coupled to the sweet vanilla was just incredible. I'm glad I didn't add the lemon because the tangy vanilla was just perfect with the rhubarb and raspberries. The density of the cake was really nice, and serving it was a dream, even with all that fruit on top. My only complaint is that the cake was a tad dry. Just a tad. I may have been a little heavy-handed with the cake flour (since my 2 cups weighed a bit more than it should have; next time I'd aim for 200 grams instead of the 260 that I measured). Or, perhaps a few minutes less in the oven is all that's needed.

Rhubarb and raspberry upside-down cake
Yields one 9-inch cake


For the fruit layer

• 1/2 stick (57 grams) unsalted butter, room temperature
• 115 grams light brown sugar
• 500 grams washed and trimmed rhubarb, cut into 1/2 inch pieces
• 160 grams frozen raspberries
• 110 grams granulated sugar
• 2 tsp cornstarch

For the cake layer

• 260 grams cake flour
• 1 1/4 tsp baking powder
• 1/2 tsp salt
• 2 tsp ground ginger
• 2 sticks (114 grams) unsalted butter, room temperature
• 220 grams granulated sugar
• 1 tsp vanilla
• 4 eggs, room temperature
• 100 mL yoghurt (2.5% fat content)

Directions:

1. Preheat the oven to 325°F.
2. Prepare a 9-inch springform pan by lining the bottom with parchment (I basically cut a large square of paper, place it on the base, then clip the sides over so that the paper runs right through the springform). Grease the paper and the sides of the springform pan. Wrap the outside of the pan with 2 large sheets of aluminum foil (in case your springform is as leaky as mine is). Place the wrapped springform pan on a greased rimmed baking sheet, and set it aside for later.

For the fruit layer:

1. In a small saucepan, melt the butter and brown sugar until it gets bubbly. Pull the pan off the heat and allow it to cool.
2. In a medium bowl, combine the fruits with the granulated sugar and cornstarch. Mix it carefully to not damage the raspberries too much, and let it sit.

For the cake layer:

1. Sift together the dry ingredients into a medium bowl and set them aside.
2. In the bowl of an electric mixer fitted with the paddle attachment, cream the butter and the granulated sugar.
3. Add the vanilla, and then the eggs, one at a time, beating well, and scraping down the sides of the bowl after each addition. Don't worry if the batter looks curdled at this point.
4. Alternately, add the dry ingredients (one-third at a time) and the yoghurt (half at a time), beginning and ending with the dry ingredients. Be sure to scrape down the sides and the bottom of the bowl occasionally.

Assembly and baking:

1. Spoon the melted butter and brown sugar mixture at the bottom of the prepared pan. Smooth it out so that it forms an even layer.
2. Disperse the fruits evenly on top of the sugar layer.
3. Pour the cake batter over the fruits being sure to smooth the top. Bang the pan on the counter so as to remove any air pockets (you could also swirl a knife through carefully to remove any air pockets, just be sure to avoid the fruits at the bottom).
4. Bake for 1 hour to 1 hour 15 minutes, until a cake tester comes out clean.
5. Let the cake cool for 15 minutes in the pan, then place your serving plate over top, and flip it very carefully because the fruit juices are boiling hot! Set the plate on a wire rack to cool completely. Do not let the cake cool in the pan because the fruits and juices will stick to the bottom, and you'll have a hard time getting it out after.