step 1

Preheat oven to 350 degrees. Line a 13 x 18-inch half sheet pan (or 9 x 13-inch baking pan, see notes below) with parchment paper and spray with nonstick cooking spray, set aside. 

step 2

In a medium bowl, whisk together the gluten free flour, baking soda, salt, and cinnamon. Set aside.

step 3

In a medium bowl, add the vanilla extract, mashed bananas, greek yogurt, and sour cream. Mix until combined, set aside.

step 4

In a stand mixer fitted with the paddle attachment, beat together the coconut oil, coconut sugar, and honey on medium speed until well combined, about 2 minutes. Scrape down the sides and bottom of the bowl. With the mixer on medium-low speed, add the eggs, one at a time, mixing until just incorporated between each addition. Scrape down the sides and bottom of the bowl, then mix on medium-low speed for 1 minute. Add the mashed banana mixture and mix on medium-low speed until just combined. Slowly add the dry ingredients and mix on low speed until the flour is just incorporated. Scrape down the sides and bottom of the bowl and mix again until flour is fully incorporated. DO NOT OVERMIX!

step 5

Spread the cake batter evenly in the prepared sheet pan. Bake for 19 to 23 minutes, or until a toothpick inserted into the center comes out clean. Allow cake to cool completely in the pan on a wire rack. 

step 6

While the cake is cooling, make the frosting. In the bowl of a stand mixer fitted with the paddle attachment or in a large bowl with a hand mixer, beat the peanut butter, butter, and cream cheese on high until light and fluffy. Add the powdered sugar, vanilla extract, and almond milk. Beat slow at first, then increase speed to high and beat for approximately two minutes. Frosting should be nice and creamy, but if it’s too thick, thin it out with a little more almond milk, 1 teaspoon at a time. 

step 7

Once the cake has cooled completely, it’s time to frost the cake. Cut out four, 6 inch round layers using a cake cutter. Place about 1 to 2 tablespoons of frosting onto a cardboard round or cake stand and spread slightly. Place one cake layer top-side down onto the dollop of frosting, add about 1/2 heaping cup of frosting to the cake layer, and spread evenly. Add another cake layer, top side down and repeat with another 1/2 heaping cup of frosting until all cake layers are stacked. Then frost the top and sides of the cake with the remaining frosting. If the frosting gets too warm at any point, place the cake and frosting into the refrigerator for about 10 minutes before continuing. Garnish cake with toasted walnuts.