Adaptable keto sponge cake

Source: just lots of experimentation

v 5.0; updated on 15/12/2019. Added chocolate variation. See in substitutions.

This is a recipe just for the sponge cake. You can stack multiple cakes and make icing for example with cream cheese to make it nice and professional. Have not tried recipe with scaling of ingredients. It is adaptable because you can swap out the vanilla extract and almond milk for other flavourings such as lemon extract and lemon juice, and you can add seasonings like cinnamon, or lemon rind.

Default flavour below is vanilla.

It is very hard to achieve rise compared with normal cake recipes, so the steps, ingredients, and their quantities should be followed precisely to avoid a flat cake.

Ingredients

• 1 cup almond flour, sifted (very important to be sifted for good rise)
• 3 tbsp coconut flour, sifted
• Granulated sweetener equivalent to 2/3 cup sugar
• 3 eggs, room temperature
• 1 tbsp butter, softened and room temperature
• 1 tbsp cream cheese
• 1.5 tsp baking powder. If you use an acidic ingredient e.g. lemon juice, cocoa powder, replace this with 0.5 tsp baking powder and 0.5 tsp baking soda (sodium bicarbonate).
• 1 tsp vanilla extract, or other flavourings such as lemon extract
• 2 tbsp almond milk, or other liquid flavouring of your choice, e.g. lemon juice.
• Additional seasonings, such as 1 tsp cinnamon, 3/4 tsp cardamom, lemon rind (from up to 2 lemons).

Substitutions

More almond flour:

• Can replace the coconut flour with an additional 1/2 cup almond flour to make 1.5 cups almond flour total. This will increase the caloric content but decrease the net carbohydrates. The flavour will be more almond-like and the texture will not have that slight coconutty tint.

Chocolate variant:

• Reduce the almond flour by 1/4 cup to make 3/4 cup almond flour total.
• Bloom 1/4 cup cocoa powder in 4 tbsp boiling water and add to batter just after adding cream cheese and vanilla.
• Increase sweetener from 2/3 cup to 3/4 cup to offset the bitterness of the cocoa powder.
• Don’t add any almond milk or alternative (the 4 tbsp boiling water above is enough).

Method

• Preheat oven to gas mark 4.
• Separate egg yolk and egg whites into separate bowls.
• In another empty bowl, add the softened butter. Gradually add the sweetener and beat the mixture. Beat until fluffy (at least 2 minutes).
• Add egg yolks one at a time, and whisk on low until all well incorporated.
• Combine together the dry ingredients: almond flour, coconut flour, and baking powder/soda in a separate bowl
• Slowly add the dry ingredients to the batter and whisk on low until well incorporated (batter is thick so will take some effort).
• Add the cream cheese, vanilla extract (or alternative), almond milk (or alternative), and any additional seasonings such as cinnamon or lemon rind. Combine until well incorporated.
• Whip the egg whites in a separate bowl until stiff.
• Gently fold in the egg white into the batter.
• Cover a 6 inch sandwich cake tin with parchment paper. Place the batter into the covered dish and bake at gas mark 4 for 1 hour (baking times may vary; ensure it is cooked by checking with a fork or cocktail stick.)
• Leave it to cool before serving.

Nutritional information for the entire cake: 1088 calories, 18g net carbohydrates, 46g protein, 88g fat, 22g fibre