Peanut butter cake

This is a peanut butter cake I made by frosting a yellow cake with peanut butter cream cheese. I've written about the yellow cake, adapted from a wonderful recipe I found in Dr William Davis's 'Wheat Belly Cookbook'. 

Peanut butter cake

Ingredients for the cake

Ingredients for the yellow cake 

yields 12 servings

2 C almond flour (finer texture will yield a fluffier cake), sifted 
¼ C coconut flour, sifted 
¼ C ground golden linseeds 
2 tsp baking powder, sifted 
½ tsp baking soda, sifted 
½ tsp pink salt 
3 large free-range eggs, separated 

6 tbsp butter, melted 
¼ C xylitol 
1 tbsp vanilla extract 

Ingredients for the peanut butter frosting

½ C buttermilk (homemade by mixing ½ C whole milk with ½ tbsp lemon juice and letting the mixture stand for 10 minutes until it thickens)

Ingredients for the peanut butter frosting

¾ C soft cream cheese
¾ C natural peanut butter (no sugar added) 
⅓ C icing sugar (made from xylitol) 
½ tsp pure vanilla bean paste
⅛ tsp  pink salt

Instructions

1. Preheat the oven to 175°C. Prepare a 9” round baking pan as needed and line it with a circle of greased parchment paper (I'm using a silicon pan).
2. In a large bowl, combine the sifted almond flour, coconut flour, ground linseeds, baking powder, baking soda, and salt.
   
3. In another separate bowl, whisk the egg yolks until smooth. Then add in the melted butter, sugar, vanilla, and buttermilk, and mix until thoroughly combined.
   
4. Gently fold the egg yolk mixture in batches into the flour mixture until well combined.
   
5. In a separate large bowl, use an electric mixer set on high speed and beat the egg whites until stiff peaks form.
   
6. Then gently fold the egg whites into the flour mixture in batches until well combined.
   
7. Pour the mixture into the cake pan, taking care not to knock out much air.
   
8. Bake in the centre rack of the oven for 35 minutes, or until the top is golden and a wooden pick inserted in the centre comes out clean.
   
9. Allow the cake to cool in the pan for 10 minutes before inverting it onto a rack to cool completely.
   
10. When the cake has cooled, make the peanut butter cream cheese frosting. Beat the cream cheese and peanut butter on high speed until creamy and smooth. Add in the vanilla and salt. Beat on medium speed for about 45 seconds to combine. 
11. In batches, mix in the icing sugar. Scrape down the sides of the bowl and continue beating on high speed until the frosting is thick and fluffy, about 3-4 minutes.
    
12. Place in the fridge for about an hour to let it firm up.
13. When the cake has completely cooled and the frosting is firm enough, spread the frosting over the cake. Cut and serve.
    

This is a beautiful cake. The base is, once again, moist and fluffy. But I was particularly pleased with the peanut butter frosting.