Iron Chef Basil: Chocolate Cake with Basil Buttercream

We had Iron Chef Basil about a month ago now, and I’m just getting around to posting my recipe. I like to choose the course that seems the most disparate with the ingredient. So for basil, that was of course dessert! I found a lot of strawberry-basil desserts but that seemed pretty classic and I wanted to challenge myself. When I found this recipe for chocolate cake with basil buttercream on The Vanilla Bean Blog, I knew I had to try it. Besides, the photos were gorgeous, and we all know that presentation is half the battle at our Iron Chef competitions. I had a lot of trouble getting the buttercream to set up, but in the end I think it tasted great. It didn’t have a lot of basil flavor that first night (darn it!) but it got stronger and stronger every day. In fact, by the fourth day, it might have been a little too strong, so you’ll want to eat it fast! This recipe is definitely kind of a process and reminds me why I don’t back layer cakes all that often, but for a special occasion (or a competition) it’s worth it. You need to start the night before to get the buttercream ready, so be prepared!

Cake Ingredients

1 3/4 cup flour

2 cups sugar

3/4 cup good cocoa powder

2 teaspoons baking soda

1 teaspoon baking powder

1 teaspoon salt

1 cup buttermilk, shaken

1/2 cup vegetable oil

2 eggs, at room temperature

1 teaspoon vanilla

1 cup freshly brewed hot coffee

This is Ina Garten’s chocolate cake recipe, and it’s very good. Mine was a bit dense because I may have overmixed it, so be careful! I think the recipe was a little hard to follow because it was written for someone with a stand mixer and surprise!—not everyone has one of those.

Start by preheating the oven to 350 and butter or spray two 8 inch round cake pans. I had non-stick pans but had a panicked moment when the cakes wouldn’t come out, so even if you do still butter. You could also put a round of parchment paper in the bottom of the pan.

Sift together the flour, sugar, cocoa, baking soda, baking powder and salt. I’m not a big sifter generally, but I would do it for this cake because of the cocoa powder. For some reason that always tends to clump up on me. Stir the ingredients together until they are well combined.

In another bowl, mix together the buttermilk, oil, eggs and vanilla until combined. Then slowly add the wet ingredients to the dry while mixing on low (it helps to have an extra set of hands for this). Next add the coffee and stir (with a spatula not the mixer) just enough to combine, scraping the bottom. I can’t stress enough not to overmix this. It will be super duper liquidy. I was nervous, but don’t be. Pour the batter into the two pans and bake 35-40 minutes until your toothpick comes out clean. Then remove from the oven and cool in the pans for 30 minutes before turning them out on to a cooling rack to finish cooling completely. Now, to make the buttercream.

Buttercream Ingredients

1 1/2 cups whole milk

1/3 cup heavy cream

1 cup fresh basil leaves, packed

1 1/2 cups granulated sugar

1/3 cup all purpose flour

1 1/2 cups (three sticks) unsalted butter, soft but cool, cut into small pieces

1 tsp pure vanilla extract

The night before stir milk, heavy cream and basil in a saucepan. I tore the basil leaves in half, thinking that it might let them seep out more basil flavor (who knows?). Heat on low until just barely simmering and then remove from heat. Let it cool to room temperature, then refrigerate overnight. When you’re ready to make the buttercream, remove the basil leaves from the cream, making sure to squeeze out the leaves.

Whisk sugar and flour together in your saucepan before adding the basil cream mixture. Cook over medium heat, whisking occasionally for 10-15 minutes, until the mixture boils and thickens. Then move the mixture to a bowl and beat on high speed until it is cool, about 7-9 minutes. I know it’s a pain to mix that long if you don’t have a stand mixer, but don’t skimp. If the sauce is too hot your buttercream won’t set.

You want your butter to be soft but cold. What I did was let it soften at room temperature, but then put it back in the fridge 10-15 minutes before I needed it. Reduce your mixing speed to low and add the butter, mixing until it’s fully incorporated. Then turn your mixer up to medium high speed and beat until the frosting is light and fluffy and frosting like! Should only take a couple minutes. Add the vanilla and mix until it’s combined.

Now you need to check the consistency. If your frosting is too soft (mine was) put it in the fridge to chill and then beat again until it’s right. If it’s too hard, you can set the bowl over hot water (simmering at most) and beat until it softens a little. Hopefully you won’t have to do either!

You should know how to frost a layer cake but just in case… start by topping one layer with frosting, then put the second layer on top. Now you’re ready to frost the rest of the cake, and decorate with a few basil leaves on top. We didn’t eat the leaves with the cake though! It’s a strange flavor combination but it definitely works, and I think the cake recipe will definitely become a staple of mine.