Brown Butter Nectarine Cake with Bourbon Whipped Cream Frosting

Hooray for stone fruit season!! Brown butter and roasted nectarines are the two star ingredients of these cake layers. They get slathered in a whipped cream frosting that has hints of brown sugar, bourbon and a little mascarpone to add that slight tang to balance it all out. This is summer. This is potluck. This is leftover snack at midnight. This is, yes please, I will take a second slice.

Now the cake takes a little planning in advance with the two main ingredients: brown butter and roasted nectarines. What is brown butter? It is literally what it sounds like. Butter is cooked over low heat, the water from the butter begins to evaporate after awhile, and the milk proteins in the butter turn brown, leaving you with a delicious toasty, nutty flavor.

For the nectarines, roasting them not only concentrates their flavor, it also helps cook out some of the liquid before baking in the cake.

Photo on left: make sure to scrape up all the browned bits off the bottom of the pan to get maximum toasty, nutty flavor.
Photo on right: After the nectarines have roasted, the peel easily comes off. I like a mixture of white (floral and sweet) and yellow (more intense flavor, slightly tangy, citrusy) nectarines.

While the butter is in liquid form, it still gets creamed together with the sugar, eggs and vanilla. Before commercial leavening agents like baking powder, creaming was an important step of whipping air into the batter in order to get the cake to rise when baking. It is still a helpful step, even when relying on baking powder.

First: Cream butter, eggs, sugar, vanilla. Second: alternately add dry ingredients with buttermilk. Third: gently fold in roasted nectarines.

Since this cake is frosted in a way that leaves the sides bare, I pulled out my kitchen scale to make sure each layer had the same amount of batter. With the little bit of whole wheat flour and all the fruit, these layers don’t rise a lot, but this simplistic, almost rustic, style of cake is one of my favorite ways to highlight fresh seasonal fruit.

Bake until golden on top

While the cake cools, whip up the frosting. If you’ve read previous cake posts of mine, you’ll know I am not a fan of buttercream. I will do anything to avoid frosting a cake with it. So this simple frosting is a glorified version of whipped cream, which is one of my favorite pairings with summer fruit. The only tip for this is to make sure and add the bourbon at the end. If it gets mixed with the cream for too long it can curdle. The bourbon can also be left out altogether if preferred.

Just the top of the cake layers get coated in the frosting for a naked cake look. Garnish the top with a few fresh slices of nectarines if desired.

We hope that you all are keeping safe this summer and doing well. Please let us know if you have any questions or comments. Happy baking!

Brown Butter Nectarine Cake with Bourbon Whipped Cream

Prep Time: 30 minutes

Cook Time: 1 hour (including roasting nectarines)

Cake:

4 medium size nectarines

115 g. (8 Tbsp.) unsalted butter

2 large eggs, room temperature

342 g. (1 1/2 cups) granulated sugar*

5 g. (1 tsp.) vanilla bean paste or extract

85 g. (3/4 cup) whole wheat flour

180 g. (1 1/2 cups) all purpose flour*

8 g. (2 tsp.) baking powder

2 g. (1/2 tsp.) baking soda

3 g. (1/2 tsp.) kosher salt

195 g. (3/4 cup) buttermilk

Frosting:

345 g. (1 1/2 cups) heavy whipping cream

1 (226 g. / 8 oz.) container mascarpone cheese, room temperature

5 g. (1 tsp.) vanilla bean paste or vanilla extract

53 g. (1/4 cup) firmly packed brown sugar*

28 g. (2 Tbsp.) bourbon, optional

fresh nectarine slices for garnish, optional

Preheat the oven to 400º F.  Cut the nectarines into quarters or halves, removing pit.  Place on a half sheet pan lined with a silicone baking mat or parchment paper.  Bake for 30 minutes.  Let cool until easy to handle and peel off skin.  Cut into chunks.  Set aside until ready to use.

Decrease oven temperature to 350º F.  Grease two 9 inch cake pans.

While nectarines are roasting, place butter in a small saucepan over low heat.  Cook, stirring frequently, until butter is a deep golden brown, approximately 5-8 minutes.  Let cool until just warm to the touch.

Place the butter, eggs, sugar and vanilla bean paste into the plastic whipping bowl with the single wire whisks.  Beat at high speed (6 o’clock) for 4 minutes.  Scrape down the sides.

In a medium bowl whisk together the flours, baking powder, baking soda and salt.  

With the mixer on low speed (12 o’clock) alternately add in half the dry ingredients, then half the buttermilk, and then repeat with remaining dry ingredients and remaining buttermilk.  Add the roasted nectarines and mix just until distributed throughout.

Divide batter evenly between the two cake pans.  Bake for 30 minutes, until top is golden brown and a toothpick inserted in the middle comes out clean.  Let cool completely before frosting.

While cake is cooling, clean out the plastic whipping bowl.  Place the whipping cream and mascarpone in the plastic whipping bowl with the balloon whisks.  Beat on medium high speed (4 o’clock) until starting to thicken.  Add in the sugar and vanilla bean paste.  Increase speed to high (6 o’clock) and whip until soft peaks.  Add in the bourbon if desired and mix just until combined.

Frost the top of one cake layer with half of the frosting.  Place the other layer on top and frost just the top with remaining frosting, leaving the sides bare.  Garnish with fresh nectarine slices if desired.  Refrigerate any leftovers because of the dairy in the frosting.

Yield: 8-10 servings

*Cooks Note: For a whole grain, less refined sugar version: all purpose flour can be replaced with 170 g. (1 1/2 cups) whole wheat flour.  Granulated sugar can be replaced with 258 g. (1 1/2 cups) Sucanat with honey, aka honey granules.  Brown sugar can be replaced with 38 g. (1/4 cup) Sucanat.

Gluten-Free Version

Made with King Arthur Gluten Free Measure for Measure Flour

-Replace both flours with 270 g. (2 1/4 cups) of a measure-for-measure/cup-for-cup gluten free flour.

-When whisking together dry ingredients, do not add the baking powder or baking soda.

-Let cake batter sit for 1 hour after mixing. Add in baking powder and baking soda after that and then bake. This gives the gluten free flour time to absorb the liquid and take away that grainy texture.

Published by

Carmi Adams

Carmi Adams has loved cooking from a very early age; requesting fondue pots and cookbooks for birthdays as a child. She further pursued her passion for food at the Art Institute of Atlanta and obtained a degree in Culinary Arts. Carmi landed a job on the show Good Eats, which aired on the Food Network. For seven years she did everything from food research, recipe development and testing, product testing to feeding a hungry film crew. Now living in the central coast of California, Carmi enjoys the bounty of agriculture, vineyards and farmers markets at her culinary disposal. She has been using the Ankarsrum mixer for over 15 years and feels that it is hands-down the best on the market for home cooks.