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+ servings
Keto Lemon cake on a sheet of parchment paper cut into 8 slices with a lemon half on the side

Keto Lemon Bars

Easy-peasy, gently sweet and super refreshing! These moist Keto lemon bars will blow you away. Check out the post for lots of topping ideas and variations, from sugar free lemon drizzle to low carb lemon curd frosting.   
Course Dessert
Cuisine British
Prep Time 5 minutes
Cook Time 35 minutes
Total Time 40 minutes
Servings 8
Calories 336kcal


  • 4 eggs large
  • 1/2 cup / 120g sour cream
  • 1/2 cup / 120g butter, softened
  • 1/4 cup / 4 tbsp lemon juice
  • zest of 1 lemon
  • 2 cup / 200g almond flour or ground almonds / NOT super-fine almond flour!!!!
  • 2 tsp baking powder
  • 1/3 cup / 40g powdered erythritol


  • Preheat the oven to 175 Celsius / 350 Fahrenheit. 
  • Beat the eggs until frothy. Add the sour cream and softened butter and blend with a food processor or electric mixer until combined.
  • Add 1/4 cup (4 tbsp) of lemon juice, the grated zest of 1 lemon and 1/3 cup powdered erythritol. Blend. 
  • Lastly, add the almond flour and baking powder and mix until you have a smooth batter.  
  • Line a 9x6 inch casserole dish / baking pan with parchment paper and fill in the dough. 
  • Bake in the middles shelf of the oven for 35-40 minutes until the top is lightly browned and a skewer inserted comes out clean. 
  • Leave to cool completely before cutting or removing from the pan. Almond flour cakes are fragile when hot, but they firm up as they cool down. 



This lemon cake recipe works best with coarse /grainy almond flour (ground almonds in the UK). 
The cake is only gently sweet. Please taste and increase sweetener to your liking if necessary.
For me, 1 1/2 lemons yielded 1/4 cup lemon juice. For extra zing, you could increase the amount of lemon juice by up to 2 additional tbsp.
Wait until the cake is COMPLETELY cooled before dusting with powdered sweetener. If it's still warm, the erythritol melts into an unsightly sludge. 
Please see the post for topping ideas, from sugar free lemon drizzle to lemon frosting. 


Calories: 336kcal | Carbohydrates: 3.6g | Protein: 10.4g | Fat: 30.8g | Saturated Fat: 11.8g | Fiber: 1.9g | Sugar: 2.6g