Whole Lemon Loaf Cake with Tangy Lemon Icing Step-by-step instructions

Before you start

Before starting, gather all ingredients and equipment. Boil the lemon first, then let it cool while you prepare the pan and preheat the oven.

Have the eggs, sugar, oil, and milk at room temperature for the smoothest blend. Line the loaf pan with parchment paper, leaving an overhang for easy removal.

Measure the confectioners' sugar and lemon juice for the icing, but don't mix it until the cake is baked and cooled. Preheat the oven to 160°C (320°F) fan (or 180°C/350°F conventional) and position a rack in the center.

Instructions

Boil and Blend

1. 1Boil and Prep the Lemon
   Place the whole lemon in a small saucepan and cover with water. Bring to a boil over high heat, then reduce to a gentle simmer. Boil for 6 minutes, turning occasionally, until the lemon is slightly softened and the skin is tender. Drain and let cool until easy to handle. Slice the lemon into quarters and carefully remove any seeds with a paring knife.
   Look for The lemon skin is tender and the fruit is slightly translucent when pierced with a knife.
   Tip Boiling the lemon softens the peel and removes some bitterness, making the whole fruit blend smoothly.
2. 2Blend the Wet Ingredients
   In an electric blender, combine the boiled lemon quarters, eggs, granulated sugar, vegetable oil, and whole milk. Blend on high for 45 seconds until the mixture is ultra-smooth and creamy, with no visible pieces of lemon. The batter will be a pale golden emulsion.
   Look for The mixture is completely smooth, frothy, and pale yellow, with a uniform texture.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip Blending thoroughly ensures the lemon is fully incorporated, giving the cake its intense flavor and moist crumb.

After boiling, the lemon should be soft and slightly translucent. When blended with the other ingredients, the mixture should be a smooth, pale yellow liquid with no visible pieces. It will look like a thick smoothie—pourable but not watery. The aroma is intensely lemony and sweet.

Bake to Golden

3. 3Prepare the Pan and Pour
   Preheat the oven to 160°C (320°F) with the fan setting (or 180°C/350°F conventional). Butter a 9x5-inch loaf pan, then line with parchment paper, leaving an overhang on the long sides for easy lifting. Pour the blended batter into the prepared pan and smooth the top.
   Look for The batter fills the pan about three-quarters full, and the top is level.
   Tip Buttering the pan even when using parchment helps the paper stick and prevents slipping.
4. 4Add the Butter and Bake
   Slice the chilled butter into thin pieces and place them down the center of the batter in a line. This helps create a crack down the middle as the cake bakes. Transfer the pan to the preheated oven and bake for 35 minutes, until the cake is puffed, split along the center, and a toothpick inserted into the thickest part comes out clean or with only a few moist crumbs.
   Look for The cake is golden brown, the top has split, and the edges pull away from the pan slightly.
   Safe temperature 160°F (71°C) internal temperature (egg dishes)
   Tip The butter line encourages a classic loaf crack; if it doesn't split, that's fine—the cake will still be tender.
5. 5Cool in the Pan
   Remove the loaf pan from the oven and place it on a wire rack. Let the cake cool in the pan for 10 minutes. Then, using the parchment overhang, lift the cake out of the pan and transfer it to the rack to cool completely before icing.
   Look for The cake is firm to the touch and has pulled away from the sides of the pan.
   Tip Cooling in the pan for 10 minutes helps the cake set without over-baking from residual heat.

The cake will rise and crack along the butter line, turning a deep golden brown. The kitchen will smell of warm lemon and sugar. A toothpick inserted in the center should come out clean or with a few moist crumbs. The cake should feel springy to the touch.

Glaze and Serve

6. 6Make the Lemon Icing
   In a small bowl, whisk together the confectioners' sugar and fresh lemon juice until smooth. The icing should be thick but pourable—if too thick, add a few drops of lemon juice; if too thin, add a little more sugar.
   Look for The icing is glossy, smooth, and coats the back of a spoon.
   Tip Whisk thoroughly to avoid lumps; the icing will thicken as it sits.
7. 7Glaze the Cake
   Drizzle the icing over the cooled cake, letting it run down the sides. Use the back of a spoon to spread it evenly if needed. Allow the icing to set for a few minutes before slicing.
   Look for The icing forms a smooth, glossy layer that slowly drips down the sides.
   Tip For a thicker glaze, let the icing sit for 5 minutes before pouring; for a thinner one, add a little more lemon juice.

The icing should be smooth and glossy, with a consistency that slowly drips off the spoon. When drizzled over the cooled cake, it forms a white, crackly top that contrasts with the golden crumb. The cake is ready to slice once the icing has set.

Common mistakes

One common mistake is not boiling the lemon long enough, resulting in tough bits in the batter. Make sure the lemon is soft and easily pierced with a knife after boiling. Overmixing the batter after blending is another issue—blend just until smooth, then pour.

Overbaking can dry out the cake; start checking at 30 minutes and rely on the toothpick test. Finally, don't skip the cooling time before icing—if the cake is warm, the icing will melt and run off.

How to tell it’s done

The cake is done when it is puffed, golden brown, and a toothpick inserted into the center comes out clean or with a few moist crumbs. The top should have split along the butter line, and the edges should pull away from the pan slightly.

The internal temperature of the cake should read at least 200°F (93°C) in the center, but the visual cues are the most reliable. If the top browns too quickly, tent loosely with foil for the last 10 minutes of baking.

• Egg dishes: 160°F (71°C) in the thickest part