Vegan Banana Oatmeal Sheet Cake

Pieces of Banana Oatmeal Sheet Cake on a wire serving platter

5 from 4 votes

Sheet cakes are the ultimate celebration treat, and this Vegan Banana Oatmeal Sheet Cake takes deliciousness to a whole new level! It's all about that delightful banana flavor, with the added goodness of rolled oats, aromatic spices, and a touch of vanilla. And let's not forget the star of the show—the incredibly delicious vegan Maple Buttercream frosting! Completely Vegan + Gluten-free option.

Prep Time15

Cook Time25

Total Time40

Course: Dessert

Keyword: baked, banana, breakfast, brunch, cake, dairy-free, dessert, oatmeal, oats, sheet cake, snack, sweet, vegan

Servings: servings

Calories: 420kcal

Author: Shanika

Ingredients

SHEET CAKE:

1 cup organic cake flour (You can also use all-purpose flour)
1 cup organic rolled oats
3 Ripe bananas, mashed
1 cup organic cane sugar
1 tablespoon baking powder
1 tablespoon ground cinnamon
1 teaspoon ground nutmeg
½ teaspoon ground allspice
¼ teaspoon ground ginger
½ teaspoon sea salt
1 teaspoon vanilla extract
1 cup Almond milk + 2 Tbsps! (You can use your fave plant-based milk!)
1 tablespoon Apple Cider Vinegar
4 Tbsps vegan butter, melted

MAPLE BUTTERCREAM:

4-5 cups organic powdered sugar, sifted
1 cup vegan butter, softened at room temp.
¼ cup pure maple syrup
1 teaspoon vanilla extract
1 teaspoon ground cinnamon
1-2 Tbsps Almond milk (You can use your fave plant-based milk!)

OPTIONAL TOPPING:

2 cups Toasted chopped pecans

US Customary - Metric

Instructions

TO MAKE BANANA OAT CAKE:

Begin by preheating your oven to 350 degrees Fahrenheit. Lightly grease and line with parchment paper (with two sides hanging out) an 8-inch square pan (for a thicker cake) or a 9 x 13 baking pan.
In a bowl, whisk together the milk and apple cider vinegar and set aside for 5-10 minutes until everything "activates".
In a large bowl, whisk together the flour, oats, sugar, baking powder, cinnamon, nutmeg, allspice, and ginger until combined.
Add in the mashed bananas, milk-ACV mixture, melted butter, vanilla, and mix (using a hand-mixer) until just combined.
NOTE: If the batter looks extremely thick, add extra milk, 1 tablespoon at a time until it’s somewhat pourable but not runny or thin at all.
Pour batter evenly into prepared pan, spreading everything around for a perfect evenness.
Bake for 20-25 minutes, or until the center of the cake comes out clean when tested with a toothpick or butter knife.
Once done, remove the cake from the oven and let cool for 30 minutes before carefully lifting it from the pan and unto a cooling rack to cool completely.

TO MAKE THE BUTTERCREAM:

Simply beat the butter in the bowl of an electric mixer (or using a hand-mixer) on medium-high speed, until smooth and pale. Add in the powdered sugar, cinnamon, maple syrup, vanilla, and milk, continuing to mix on medium-speed until you reach the desired consistency----smooth and fluffy. NOTE: Add more milk (1 tablespoon at a time if too thick) or powdered sugar (for more thickness).
Using a metal or rubber spatula, top cooled cake with buttercream frosting and evenly spread over the top until fully coated and smooth. Top with toasted chopped pecans, if desired. Wallah!
Slice into medium-sized squares and enjoy!
Bon Appetit!

Notes

STORAGE: Keep leftover cake tightly wrapped using plastic wrap and refrigerated for up to 5 days. To store frozen (frosted or unfrosted), simply tightly wrap and cover cake and freeze for up to 2-3 months. To serve, thaw in the refrigerator overnight and bring to room temperature.
CUPCAKES: This recipe yields about 30 cupcakes. Simply bake for 18-20 minutes instead, until centers come out clean.
FLOUR: If you don’t have cake flour, you can always just use all-purpose flour instead.
MAKE AHEAD: You can always bake this cake the night or day before and let it cool, tightly wrap, and refrigerate until ready to use. The buttercream frosting can also be made prior and tightly wrapped and stored in the fridge as well. When ready to serve, let cake sit at room temperature for 30 minutes to an hour, frost, and enjoy!
OIL VS. BUTTER: Instead of vegan butter, you can also use Vegetable or Coconut oil, if preferred.
GF OPTION: If you want to make this cake Gluten-Free, you can simply substitute flours with Bob's Red Mill's 1-to-1 Baking Flour and ensure that the Rolled oats are GF-certified. Just add an additional ¾ cup or so if needed; To use other GF flours such as coconut, almond, etc. just be sure to add 1 teaspoon of Xanthan gum.

Nutrition