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interior of banana cream cake
4.80 from 5 votes

Banana Cream Cake

Banana cream cake features four banana cake layers sandwiched with fresh banana slices, vanilla pastry cream, and vanilla Swiss buttercream.
Yield: 6-inch layer cake
Prep Time: 45 minutes
Cook Time: 30 minutes
Assembly: 30 minutes
Total Time: 1 hour 45 minutes
Course: Dessert
Cuisine: American
Servings: 12
Calories: 729kcal
Author: Maryanne Cabrera

Ingredients

Banana Cake:

  • 200 grams all-purpose flour (1 ½ cup)
  • 1 teaspoon baking powder
  • ½ teaspoon baking soda
  • ¼ teaspoon kosher salt
  • 113 grams unsalted butter , softened (½ cup)
  • 150 grams granulated sugar (¾ cup)
  • 2 large eggs , room temp
  • 1 ½ teaspoon pure vanilla extract
  • 175 grams mashed ripe bananas (2 medium bananas or about ¾ cup)
  • 90 grams sour cream (6 Tablespoon)

Pastry Cream Filling:

  • 454 grams whole milk (2 cup)
  • 150 grams granulated sugar ( ¾ cup)
  • 32 grams cornstarch ( ¼ cup)
  • 4 large egg yolks
  • ¼ teaspoon kosher salt
  • 28 grams unsalted butter (2 Tablespoon)
  • 2 teaspoons pure vanilla extract
  • 2 medium bananas , thinly sliced

Swiss Meringue Buttercream:

  • 190 grams egg whites (¾ cup) about 6 large eggs
  • 300 grams granulated sugar ( 1 ½ cup)
  • 452 grams unsalted butter ( 2 cup), sliced into tablespoons, room temp
  • ¼ teaspoon kosher salt
  • 1 ½ teaspoon pure vanilla extract

Instructions

Banana Cake:

  • Preheat oven to 350°F. Line two 6-inch round cake pans with parchment paper. Grease well. Set aside.
  • In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
  • In the bowl of a stand mixer fitted with paddle attachment, cream butter, sugar, and vanilla until smooth. Scrape down sides of bowl as needed.
  • Mixing on low speed, add eggs one a time. Add in mashed bananas. Mix on medium speed until well combined. *The batter may look curdled.
  • Add half of dry flour mixture. Mix on low speed until almost incorporated. Follow with sour cream. Mix. Then, add remaining half of dry flour. Mix on low speed until just combined. Finish mixing by hand to ensure there are no longer any dry streaks of flour.
  • Divide batter between the two prepared cake pans (about 390 grams each). Bake in the center rack of oven for 30 minutes, rotating pans midway through baking.
  • Cool cake in pans for 10 minutes. Run mini offset spatula along the perimeter of cake pans to loosen cake. Unmold cake. Cool cakes to room temperature on wire rack.

Pastry Cream Filling:

  • Line a half-sheet baking pan with plastic wrap, making sure the sides of the tray are also covered. Set aside.
  • Pour 1 ½ cup of milk into a large heavy bottomed saucepot. Add 2 Tbsp (25 grams) of sugar. Stir together. Place over medium-high heat and bring to a boil. Stir occasionally to ensure milk does not burn along the sides or bottom of pan.
  • Meanwhile, In a large bowl, whisk together cornstarch and remaining ½ cup + 2 Tbsp (125 grams) sugar. Add egg yolks and remaining ½ cup milk. Whisk until smooth.
  • Once milk has a come to boil, reduce heat. Slowly add a little bit bit of the hot milk (about ⅓ cup at a time) into the egg mixture. Whisk constantly to distribute to heat. Continue until only a couple tablespoons of milk are left in the saucepot. Then, pour all the egg-milk mixture back into the saucepot.
  • Whisk constantly over medium heat until the custard has thickened. (Use a whisk or a spatula) Keep stirring, ensuring to scrape the bottom and sides of the pot. Let custard come to boil to cook out the cornstarch flavor. Remove from heat.
  • Whisk in butter until melted and distributed. Add vanilla and whisk until combined.
  • Pour the hot pastry cream into the prepared plastic wrapped sheet pan. Spread into an even layer. Cover the cream directly with plastic wrap. Freeze for 10-15 minutes until the pastry cream has cooled to room temperature.
  • Remove from the freezer. Continue to cool in refrigerator until ready to use.

Swiss Meringue Buttercream:

  • In the bowl of a stand mixer, whisk together egg whites and sugar. Place over a pot of simmering water to create a bain-marie or double boiler. Make sure the simmering water does not touch the bottom of the bowl. Whisk mixture until it reaches a temperature of 160°F.
    *Alternatively, if you don't have a thermometer, heat the mixture until all the sugar has melted. Test this by dipping your pointer finger into the mixture and rubbing it against your thumb. The mixture should feel smooth. You should not be able to feel the granules of sugar.
  • Return bowl to stand mixer. Using the whisk attachment, beat mixture at medium speed until it has cooled to room temperature (about 75-80°F) and meringue has started to form.
  • Reduce to low speed. Add butter one tablespoon at a time. Add salt and vanilla. Increase speed to medium-high and continue to beat until buttercream is light and fluffy.

Assembly:

  • Thinly slice bananas for filling. Cover and set aside. Remove pastry cream from fridge. Transfer to a bowl. Use a whisk or sturdy spatula to refresh and smooth pastry cream. Set aside.
  • Fit a piping bag (also called pastry bag or decorating bag) with a small round tip. Fill bag with about ½ cup of buttercream. Set aside.
  • Level cake layers as necessary. Split each cake round in half lengthwise to create a total of 4 cake layers.
  • Place one cake layer on serving platter or cake turntable. Use a mini offset spatula to spread a thin layer of buttercream (about 2 Tbsp) over cake layer.
  • Use the filled piping bag to pipe a border of buttercream along the perimeter of cake round. This will serve as a barrier.
  • Arrange a layer of sliced bananas within the buttercream border. Top bananas with pastry cream. Use a mini offset spatula to spread pastry cream in an even layer within the buttercream border.
    *Amount of pastry cream used is depending on the thickness of the banana slices.
  • Place second cake layer on top. Repeat spreading buttercream, piping border, adding banana, and pastry cream until the final fourth cake layer is added on top.
  • Spread buttercream all over the cake to create a "crumb coat" layer to seal in any crumbs. Chill cake in the fridge for about 20 minutes to set frosting.
  • If desired, coat chilled cake with additional buttercream. Decorate cake as desired.
  • Keep cake chilled until ready to serve. Rest cake at room temperature for about 30 minutes to soften buttercream frosting before serving.

Notes

Recipe makes plenty of pastry cream and buttercream. More than you need for this recipe. 
  • Store leftover pastry cream in the fridge in an airtight container for up to three days. Use to make parfait, fill donuts, fill pie, etc. Or, just eat straight out of the bowl!
  • Store leftover buttercream in an airtight container in the fridge for up to three ays. Or, freeze for up to two months. 
Serving Suggestions:
  • Cold cake directly out of the fridge is the easiest to slice into clean portions.
  • Use a sharp knife to slice cake. Wipe knife clean after each slice.
  • A 6-inch round layer cake can easily serve 10-12 wedge slices
Storage & Leftovers:
  • Store uncut assembled cake in the fridge for up to two days before slicing.
  • Once sliced open, cover exposed sliced cake with plastic wrap, wax paper, or parchment paper to prevent cake from drying out. Keep in an airtight container in the fridge. 
  • Overtime, the fresh banana slices will oxidize and turn brown. Though still edible, the color is a bit unappealing.
  • The cake and buttercream will be dense immediately out of the fridge. Let cake and frosting come to room temperature before eating. The buttercream should be silky smooth and cream at room temperature.

Nutrition

Calories: 729kcal, Carbohydrates: 76g, Protein: 8g, Fat: 46g, Saturated Fat: 28g, Polyunsaturated Fat: 2g, Monounsaturated Fat: 12g, Trans Fat: 2g, Cholesterol: 207mg, Sodium: 291mg, Potassium: 266mg, Fiber: 1g, Sugar: 57g, Vitamin A: 1492IU, Vitamin C: 3mg, Calcium: 104mg, Iron: 1mg