Gluten-Free Peanut Butter Cake

This easy to make Peanut Butter Cake is smothered in a fluffy peanut butter buttercream. Made as a simple traybake this snacking cake is perfect for serving to a crowd and has a rich and irresistible peanut butter vanilla flavour.

Prep Time1

Cook Time35

Total Time1 35

Course: Cake

Cuisine: British

Servings:

Calories: 479kcal

Author: Georgina Hartley

Ingredients

140 g blanched peanuts
140 g gluten-free all-purpose flour*
2 teaspoons baking powder
¾ teaspoon kosher salt
180 g natural unsweetened peanut butter
200 g soft light brown sugar
80 g olive oil
3 eggs medium*
2 teaspoons vanilla extract
240 g whole milk
1 tablespoon apple cider vinegar

Peanut Butter Buttercream Frosting

220 g unsalted butter
220 g icing sugar
150 g natural unsweetened peanut butter
25 g whole milk
1 teaspoon vanilla extract
¼ teaspoon salt
30 g salted peanuts roughly chopped*

Metric - US Customary

Instructions

Pre-heat the oven to 180°C / 160°C fan assisted / gas mark 4 / 350°F and line and grease a 30 x 20 x 5cm (8 × 12 × 2 inch) baking tin with parchment paper.
Pour the milk into a small bowl or jug and stir in the apple cider vinegar. Set aside for 5 minutes.
Place peanuts in a food processor with 4 tablespoons of the brown sugar. Process the peanuts until finely ground.
Whisk together the ground peanuts, gluten-free all-purpose flour, baking powder, and salt in a large mixing bowl until well combined. Set aside.
In a separate large mixing bowl, mix together the peanut butter, olive oil, sugar, eggs and vanilla until smooth and creamy. It’s possible to mix by hand but you can use handheld electric beaters if you prefer.
Gradually pour in the vinegar milk (which will look slightly curdled) into the wet ingredients and continue mixing until the batter is smooth and well combined.
Make a well in the centre of the dry ingredients and pour in the wet ingredients, stirring until everything is well incorporated.
Pour the cake batter into the prepared baking tin and place in the pre-heated oven. Bake for 30-35 minutes, or until a toothpick inserted into the centre of the cakes comes out clean.
Remove from the oven and allow to cool in the tin for 10 minutes before transferring to a wire rack to cool completely before covering with the buttercream.

Peanut Butter Buttercream Frosting

Beat together the butter and icing sugar in a large mixing bowl with an electric mixer on low speed for about 3-4 minutes, until creamy, light and pale in colour. Scrape down the bowl occasionally to achieve an even mix.
Add the peanut butter, milk, vanilla extract and salt and mix again for a further minute until the buttercream is smooth and creamy.
Apply your buttercream to your peanut butter cake using a palette knife to create easy deep smooth swirls. For a little more of a flourish you could pipe the buttercream on using a piping bag fitted with your favourite piping tip.
Scatter over roughly chopped salted peanuts to finish, then slice and serve.

Video

Notes

Eggs. The eggs used in this recipe are medium size, 60g each with shell and 50g without shell. If you can't get hold of medium eggs I suggest you weigh the amount.

Gluten-Free Flour. This recipe will work with your favourite gluten-free flour blend. It has been tested with Doves Farm Gluten-Free Plain White Flour and my Homemade Gluten-Free Flour Blend. No xanthan gum is needed for this recipe, however if your blend does contain xanthan gum then that will work fine too.

Homemade Roasted Salted Peanuts. Toss 30g of peanuts with ⅛ teaspoon of salt and roast them at 220°C / 200°C fan assisted / gas mark 7 / 425°F for 7-8 minutes.

Make Ahead: You can make and store the peanut butter sponge up to 2 days before covering with the buttercream.

Store: You can store this cake in an airtight container for up to 3 days, it doesn’t need to be refrigerated as long as it’s stored in a cool dark place.

Freeze: The sponge cake will keep well in the freezer for up to 2 months. First wrap it tightly in plastic wrap then aluminium foil. Don’t forget to label including the date. To enjoy, thaw at room temperature overnight before frosting and serving.

Dairy-Free version: You just need to swap the whole milk in the sponge and buttercream for your favourite plant-based milk (I like almond milk here). And then for the butter in the buttercream you can use your favourite dairy-free butter. I find most brands work quite well in buttercream.

Ingredient measurements: Please note when you see ‘grams’ listed as opposed to ‘millilitres,’ or any other term of measurement, that is not incorrect. I weigh all of my ingredients, including liquids, for accuracy.

US customary measurements: These US measurements for the ingredients provided are based on a conversion calculator. This recipe was tested with metric measurements and I recommend using a digital scale to weigh ingredients for the most accurate results. READ MORE >>> Why you should always weigh vs measuring with cups.

Nutrition information: Please note that the nutrition information provided below is an estimate based on an online nutrition calculator. It will vary based on the specific ingredients you use. Please seek a professional nutritionist’s advice for further clarification.
The nutrition serving is for 1 slice of cake, assuming the cake is cut into 16 servings.

Nutrition