Are you ready to shine at your Thanksgiving or friendsgiving dinner? Make this brown butter sweet potato cake with chocolate ganache and molasses buttercream and you’re sure to be the hit of the party.
While cookies are my favorite baked good to make (no surprise there), beautiful towering layer cakes always impress me. I’m not typically a cake lover (yet another reason I’m #teamcookie), but the other day when someone asked me for some of my favorite blog recipes, the amazing pumpkin pie cake from last year and the popular chocolate cake with whiskey caramel buttercream and dark chocolate ganache frosting from earlier this year were both at the top of the list. I take this to mean two things. First, because I’m not a big cake person, I only post cakes I love, which makes them rise to the top of the list. Second, thought they take longer to make, cakes feel fancy and exciting. After all, I keep cookie dough to bake at a moments notice for everyday occasions, but layer cakes are reserved for special occasions. Today, I’m bringing you a cake that fits in both of those categories. Sweet potato cake with chocolate ganache and molasses buttercream is both a cake I really love and is perfect for special occasions like a big Thanksgiving or friendsgiving meal.
This sweet potato cake with chocolate ganache and molasses buttercream is like a big Thanksgiving hug in cake form. The sweet potato and molasses flavors bring back memories of scooping sweet potato casserole onto my plate at my grandmother’s house every year, and the brown butter flavor comes through just enough to enhance the flavor of the cake without taking over.
One bite of that thick slice of cake garners the nostalgia of a full stomach and full heart as loved ones sit around the table after a big Thanksgiving meal, too stuffed to eat anything else, but still eager to fit in one more bite of dessert before the tryptophan kicks in for the evening.
Standing tall with three layers and two types of filling, this cake is sure to impress. Go the extra mile and pipe leftover frosting or marshmallow cream on top, sprinkle it with cocoa powder and cinnamon, and you have a cake that is sure to wow guests not only with it’s looks, but also with it’s delicious taste. It is those little details that don’t take long (you already have the frosting whipped up and would otherwise throw it away, right?), but make the cake special occasion-ready.
Brown Butter Sweet Potato Cake with Bourbon Molasses Frosting and Chocolate Ganache Filling
Updated 12.10.2018 with ganache and assembly instructions
Sweet Potato Cake
22 oz baked sweet potatoes (almost 2 pounds of unbaked sweet potatoes, or about 4-6 medium sweet potatoes)*
3 cups flour
1 ½ teaspoons baking powder
1 ½ teaspoons baking soda
1 ½ teaspoons salt
1 ½ teaspoons ground cinnamon
½ teaspoon grated nutmeg
½ teaspoon ground ginger
1/8 teaspoon ground cloves
2 cups (4 sticks) butter
1 ¼ cups brown sugar
1 ¾ cups sugar
2 teaspoons vanilla
*The first time I tried to make this cake I measured my sweet potatoes before baking them, then when I measured after they were baked the amount wasn’t nearly the same. I used about 4-5 medium sweet potatoes (almost 2 pounds of unbaked sweet potatoes), which turned out to be just about 22 ounces, with a little extra for tasting. If you don’t have a kitchen scale, you can go measure almost 2 pounds of unbaked sweet potatoes at the grocery store before you buy them and use that measurement.
Sweet Potato Cake
Roast the sweet potatoes: Preheat oven to 400 degrees F and line a baking sheet with parchment paper. Prick sweet potatoes all over with a fork and place on your baking sheet. Roast for about 1 hour, or until the potatoes are soft and begin to caramelize. Let them rest until they are cool enough to touch. If you are not baking the cake right away, these can be kept in fridge for up to three days. Peel the cooled sweet potatoes and mash the orange potato.
Brown the butter: Melt butter in saucepan over medium heat. Cook, swirling occasionally, until butter turns brown and has a nutty smell. Remove from the heat and let cool completely. The butter is ready when it feels like a room temperature stick of butter. To speed up this process you can place the browned butter in a bowl in the fridge.
Preheat oven to 350 degrees F. Butter three 8″ round pans and line with parchment paper circles, then butter again and coat with flour.
In large bowl whisk together the flour, baking soda, baking powder, salt, cinnamon, ginger, and cloves. Set aside.
In the bowl of an electric mixer fitted with a paddle attachment, beat the butter, sugar, and brown sugar on medium-high until pale and fluffy, about 2 to 4 minutes.
With the mixer on low, add the eggs one at a time, mixing well after each egg. Add the vanilla and mix until combined. Scrape down the sides and bottom of the bowl.
Add the flour mixture in two batches. Do not over mix. I mixed too much the first time I made this cake and it came out extremely dense. Learn from my mistakes and mix just until no streaks of flour remain, then stop. Scrape down the bowl again.
Gently fold the mashed sweet potatoes into the batter with a rubber spatula.
Divide batter evenly between the three 8″ round pans and bake for 30-32 minutes, until toothpick inserted into center comes out clean. Let cool in pans for 10 to 15 minutes, then remove to wire rack to finish cooling.
Bourbon Molasses Buttercream
10 large egg whites
3 cups granulated sugar
6 tablespoons molasses, divided
4 cups (8 sticks) unsalted butter, at room temperature
3 tablespoons bourbon
Boil a small saucepan (or double boiler) of water. In a heatproof bowl, lightly whisk egg whites, sugar, and 2 tablespoons molasses in over, but not touching, the boiling water. You want to gently heat the eggs so they get warm but not cooked. Whisk until the sugar is completely dissolved and the mixture is warm to the touch (it should reach 155 to 160 degrees F on a candy thermometer). Transfer the egg white-sugar mixture to the bowl of an electric mixer fitted with the whisk attachment. Beat on high speed for about 8-10 minutes, until the meringue is shiny, holds stiff peaks, and has cooled to room temperature. The outside of the mixing bowl should be room temperature when you touch it.
Swap the whisk attachment for the paddle attachment and begin to add the butter, a couple of tablespoons at a time, mixing well after each addition. Adding the butter too quickly can cause your buttercream to curdle. After all of the butter has been added, increase speed to high and beat until thick and very fluffy. Stop the mixer and add the bourbon. Mix on medium speed and stream in the additional 4 to 6 tablespoons of molasses, depending on your preference (I like to use 6). Beat again until molasses is thoroughly mixed and frosting is still fluffy. Use immediately, or cover and refrigerate in an airtight container until ready to use. If you refrigerate the buttercream, let it warm to room temperature before using and beat it again until it becomes fluffy again. If your buttercream is too liquidy to use, place it in the fridge for about 15 minutes, then beat it again.
8 ounces chopped dark or bittersweet chocolate
1 cup cream
In a small saucepan over medium-high heat, bring the cream just to a boil. Pour the chocolate into a medium bowl then pour the hot cream over the chocolate. Let it sit for 5 minutes, then whisk until the ganache is smooth and shiny and the cream and chocolate are fully combined. This might take a while and you will feel like it isn’t working at first. Scrape down the sides and bottom of the bowl with a rubber spatula to incorporate all of the chocolate. Let the ganache cool almost to room temperature before using on the cake.
Place the first cake layer on your cake stand and top with a layer of buttercream. Once your buttercream is even across the cake layer, add a layer of ganache, leaving a little room all around the sides so it doesn’t spill out. Repeat these steps with the second layer, then add the third cake layer and spread a coat of buttercream all around the sides and top of the cake. Use any leftover buttercream to pipe decorations on the top and sides of the cake then sprinkle with cocoa powder and cinnamon.