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Squares of baked lemon slice with lemon frosting, served on a white cake stand

Baked Lemon Slice

The easiest and most delicious Baked Lemon Slice.... with the BEST creamy & tangy lemon frosting - this is such a quick, simple and classic slice recipe.
5 from 28 votes
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Course: Slices
Cuisine: western
Prep Time: 10 minutes
Cook Time: 20 minutes
Total Time: 30 minutes
Servings: 16 pieces
Calories: 238kcal

Equipment

  • Stand-mixer, beaters or Thermomix
  • Oven

Ingredients

  • 115 g butter softened to room temperature
  • 150 g (¾ cup) caster sugar
  • lemon zest from 1 lemon
  • 2 eggs room temperature
  • lemon juice from 1 lemon
  • ½ tsp baking powder
  • 95 g (¾ cup) plain flour

For the frosting

  • 270 g (1 ¾ cup) pure icing sugar sifted, see notes
  • 65 g butter softened
  • 4 tbs lemon juice (extra if needed)

Instructions

Conventional Method

  • Preheat oven to 170 degrees celsius (fan-forced). Grease and line a 20cm x 20cm cake tin with baking paper. Set aside. 
  • Place the butter, caster sugar and lemon zest into a large bowl. Beat until smooth and creamy. 
  • Add the eggs and lemon juice and beat to combine. 
  • Fold through the baking powder and flour. 
  • Spoon the mixture into the prepared tin and bake for 20-25 minutes or until a skewer inserted into the middle comes out clean. 
  • To prepare the frosting, place the icing sugar, butter and lemon juice into a bowl. Whisk until smooth and creamy. If the frosting is a little too thick, add a bit more lemon juice and whisk again.
  • Spread the frosting over the cooled slice and allow to set. 

Thermomix Method

  • Preheat oven to 170 degrees celsius (fan-forced). Grease and line a 20cm x 20cm cake tin with baking paper. Set aside. 
  • Place the butter, caster sugar and lemon zest into the Thermomix bowl. Insert the butterfly and mix for 30 seconds, Speed 4. Scrape down the sides of the bowl and repeat until smooth and creamy. 
  • Add the eggs and lemon juice and mix for 10 seconds, Speed 4, to combine. Remove the butterfly.
  • Add the baking powder and flour and mix for 10 seconds, Speed 4. Scrape down the sides and repeat for a further 5 seconds. 
  • Spoon the mixture into the prepared tin and bake for 20-25 minutes or until a skewer inserted into the middle comes out clean. 
  • To prepare the frosting, place the icing sugar, butter and lemon juice into the Thermomix bowl and mix for 20 seconds on Speed 4. Scrape down the sides of the bowl with a spatula. Mix for an extra 30 seconds, Speed 4.
  • Spread the frosting over the cooled slice and allow to set. 

Video

Notes

RECIPE NOTES & TIPS
Use pure icing sugar (as compared to icing sugar mixture) as it will set the frosting firmer than icing sugar mixture. This is especially important when sending the slice in school lunch boxes.
If your frosting is too thick to spread, add a small amount of extra lemon juice and mix again. If your frosting is too soft, add some extra sifted icing sugar.
Storing & Freezing: Store slice in an airtight container for up to 5 days, or wrap well and freeze for up to 1 month. Allow to thaw before consuming.
 

Nutrition

Calories: 238kcal | Carbohydrates: 37g | Protein: 2g | Fat: 10g | Saturated Fat: 6g | Cholesterol: 45mg | Sodium: 89mg | Potassium: 39mg | Fiber: 1g | Sugar: 28g | Vitamin A: 310IU | Vitamin C: 1.5mg | Calcium: 14mg | Iron: 0.6mg