Pistachio Cake with Honey Vanilla Buttercream

I loved this cake! It was so different! I was afraid the cake texture would be too nutty, but it came out tender and fluffy. The buttercream was very different too. I wasn't sure if that hot milk was actually going to whip up but it did and it reminded me of a swiss meringue buttercream in texture, except better! I loved the addition of honey, but I was thinking this cake would be wonderful with a dark chocolate ganache as well. Maybe next time I'll pour some over the top!

I was also skeptical about the ice water. Coffee is added to chocolate cake batter to enhance the flavor and milk or buttermilk is added to most other cakes but ice water? How is that going to add any flavor? I don't think it did, but it did something wonderful for the cake texture. It really made this cake light and refreshing. Milk may have made it too dense and heavy. This cake didn't taste sinful at all, so if you want alittle more richness, I am contemplating making this again with half ice water and half milk.

Pistachio Cake with Honey Vanilla Buttercream
Adapted from: Joanne Eats Well with Others

Cake
1 cup shelled pistachios
2½ cups cake flour
¾ cup all purpose flour
1 tbsp baking powder
1 tsp baking soda
¾ tsp salt
3 large egg whites, at room temperature
¼ tsp cream of tartar
1 cup unsalted butter, softened
1¾ cups sugar
1 tbsp vanilla extract
1 large egg
1 cup ice water

Directions
Preheat the oven to 325 degrees F. Grease and line three 8-inch cake pans with parchment paper. Try not to use dark pans because they brown the cake edges alittle more.

In the bowl of a food processor, pulse the pistachios until it is coarsely chopped. Remove 2 tbsp to a small bowl, and reserve to garnish cake. Pulse the remaining pistachios until they have almost a powder-like consistency. Transfer to a large bowl and whisk together the fine pistachios with the all purpose flour, cake flour, baking powder, baking soda, and salt. Set aside.

In a very clean bowl of a stand mixer, fitted with a whisk attachment, whisk together the egg whites with the cream of tartar until soft peaks form, about 3-5 minutes. Transfer to another bowl and set aside.

Without needing to clean the bowl of the stand mixer, cream the butter in the stand mixer for 3 minutes, fitted with a paddle attachment. Add in the sugar and vanilla and beat until fluffy, about 3 minutes. Scrape down the sides of the bowl. Add in the whole egg and mix until just combined.

Turn the mixer to low. Pour 1 cup ice water into a measuring cup. Add the flour/pistachio mix to the batter in three additions, alternating with the ice water, mixing each time until just combined. Scrape down the bowl and mix on low speed for a few more seconds.

Fold the egg whites into the batter.

Divide the batter evenly among the cake pans and smooth the tops. Bake for 40-45 minutes, rotating the pans halfway through baking, until a toothpick inserted in the center comes out clean. Transfer to a cooling rack and let cool for 20 minutes. Flip the cakes out of the pans, onto the rack and let cool completely before frosting. Remove parchment paper from the bottoms.

Honey Vanilla Buttercream
1½ cups sugar
⅓ cup flour
1½ cups milk
⅓ cup heavy cream
1½ cups unsalted butter, soft, cut into small pieces
1 tsp vanilla extract
3 tbsp honey

Directions
For the buttercream, in a medium heavy saucepan, whisk together the flour and sugar. Add in the milk and cream and cook over medium heat, whisking frequently, until the mixture comes to a boil and then thickens, 10-15 minutes.

Transfer the hot milk mixture to a stand mixer bowl and mix with the paddle attachment on high speed until cool, about 9 minutes. Reduce the speed to low and add the butter, a few pieces at a time, until it is full incorporated. Increase the speed to medium-high and beat until light and fluffy, a few minutes.

Add in the vanilla and honey and continue mixing until combined. If the frosting is too soft, chill it and mix again.

To assemble the cake, place one cake layer top side up on a serving platter. Use a long serrated knife to cut the top so that it is flat and even. Spread a little over a cup of frosting on top. Add the next later and, again, trim so that it is flat. Top with another cup of frosting. Add the remaining cake layer and trim the top again. Spread cake with a very thin layer of frosting for the crumb coating. Put in the freezer for 5-10 minutes. Spread the sides and top of the cake with the remaining frosting and decorate as desired.