I got an email recently from my friend Bonnie, wondering what would happen if she substituted butter for the Crisco called for in her mom’s “crazy delicious” rhubarb coffee cake recipe. I sympathized with her dilemma, having borne the wrath of a sibling for having made exactly such a swap in a beloved family cookie recipe. Messing with tradition can be tricky business.
But I replied to her query by saying, “The cake will be more delicious, that’s what will happen.” And I asked for the recipe.
Now, the last time I set out to make a rhubarb cake things did not go as planned. There was no rhubarb to be found anywhere in the lower southwest quadrant of Manhattan last April. This time the universe was on my side: There was a veritable bushel of rhubarb waiting for me the first place I went looking. This never, ever happens in Paris (though it is just the latest of a string of strange and lovely developments and coincidences that has me convinced that there are favorable astral forces currently at work. I have no other explanation.)
Back to the cake. There are some things that may seem off when you’re putting this together: First, the amount of sugar may seem excessive. Remember, though, rhubarb is sour sour sour, so the sweetness is actually needed.
Second, the batter is super thick. If you have a stand mixer, lucky you: Use it, on low speed to incorporate the dry ingredients and you will have an easier time than I did by hand. Honestly, I thought the amount of flour was off but then I realized that the rhubarb would give up lots of juice during baking.
With apologies to Bonnie (and her mom), I rewrote the method slightly to reflect how I always make butter cakes. I also added some orange zest to the batter.
The cake remains super moist on the inside while developing a very satisfying crust on top. Is it as “crazy delicious” as claimed? I think so.
Rhubarb and Sour Cream Coffee Cake
(adapted from a recipe from my friend Bonnie, who adapted it from her mother)
For the topping:
1/2 c (100 g) sugar
1/2 c (40 g) untoasted nuts (I recommend sliced almonds or pecan halves)
1 t cinnamon
pinch of salt
1 T (15 g) butter, melted
For the cake:
4 oz (115 g) butter, soft and at room temperature
1 1/2 c packed (340 g) light brown sugar
1 t freshly grated orange zest
1 egg, at room temperature
2 c (280 g) all-purpose flour
1 t baking soda
1/2 t salt
1 c (240 g) sour cream (or crème fraîche, of course)
8 oz (225 g)rhubarb, cut into 1/2″ pieces (a generous 1 1/2 c)
1. Preheat the oven to 375° (190° C). Butter a 9″ or 10″ round or square cake pan or deep pie dish.
2. Make the topping: In a small bowl, combine the sugar, nuts, cinnamon and salt, then stir in the melted butter, mixing gently until it is evenly distributed. Set aside.
3. With a hand mixer or standmixer fitted with the paddle, beat the butter until it’s very smooth. Add the brown sugar and orange zest and continue mixing until light and smooth (it won’t get super fluffy). Add the egg and mix for another minute, stopping to scrape down the sides once or twice.
4. Sift together the flour, baking soda, and salt. Add this dry mix to the butter and sugar in three additions, alternating with two additions of sour cream (dry, cream, dry, cream, dry), mixing gently but thoroughly each time. Stir in the rhubarb by hand.
5. Spread the batter in the prepared pan. Distribute the topping evenly on top of the batter. Bake 55-65 minutes, until the tip of a knife inserted in the center of the cake comes out with just a few moist crumbs. If the topping starts to get too dark before the cake is done, cover it loosely with aluminum foil.
This is just the thing for a Mothers’ Day brunch, I think. Or breakfast or tea or whenever. You will want to eat this warm, no doubt, but please let the cake cool before you dig in: It will both slice more easily and taste better, I swear.