Dreamy Lemon Curd Blueberry Loaf
This lemon curd blueberry loaf is a buttery, tangy-sweet cake swirled with homemade lemon curd and packed with juicy blueberries. Kefir or buttermilk keeps the crumb tender, while layers of lemon curd create gooey ribbons throughout every slice.
Equipment
- Loaf pan
- Parchment paper
- Stand mixer
- Paddle attachment
- Tea towel
- spatula
- Mixing bowl
- measuring cups
- measuring spoons
- Cake tester
- wire rack
- aluminum foil
Ingredients
Dry Ingredients
- 260 g all-purpose flour 2 cups; plus a spoonful for tossing blueberries and extra for flouring the pan
- 200 g granulated sugar 1 cup; plus a couple tablespoons for sprinkling on top if desired
- ½ tsp fine sea salt
- 2 tsp baking powder
Wet Ingredients and Fruit
- 170 g butter 3/4 cup, softened; plus extra for greasing the pan
- 2-3 lemons zested
- 2 large eggs room temperature
- 165 g kefir 2/3 cup; full-fat buttermilk may be used instead
- 1 cup fresh blueberries or use frozen blueberries without thawing; toss with a little flour before folding in
Lemon Curd Layer
- ½ batch lemon curd homemade or store-bought; make ahead and have ready before starting the batter
Optional Topping
- 2 tbsp granulated sugar optional, for a crackly sugar crust
- simple glaze optional, add after cooling for extra sweetness
- streusel topping optional, use instead of sugar sprinkle for extra crunch
Instructions
- Make or prepare the lemon curd ahead of time so it is ready before you begin the batter.
- Preheat the oven to 350°F. Butter and flour a loaf pan, then line it with parchment paper for extra insurance against sticking.
- In the bowl of a stand mixer fitted with the paddle attachment, add the flour, softened butter, granulated sugar, lemon zest, fine sea salt, and baking powder.
- Mix on low speed for about 5 minutes, draping a tea towel over the bowl if needed to prevent flour from escaping, until the mixture looks sandy and the butter has coated the flour.
- Add the eggs one at a time on medium speed, allowing each egg to fully incorporate before adding the next.
- Pour in the kefir or full-fat buttermilk and beat for 3 to 5 minutes, until the batter looks airy, fluffy, and light.
- Toss the blueberries with a spoonful of flour, then gently fold them into the batter so they do not burst or turn the batter purple.
- Spread about one quarter of the batter into the prepared loaf pan in an even layer.
- Dollop some lemon curd over the batter and gently smooth it out, keeping the curd away from the very top surface where it could burn.
- Repeat layering with more batter and more lemon curd, aiming for about 3 curd layers and 4 batter layers. Make sure the final top layer is plain batter with no lemon curd peeking through.
- Sprinkle a couple tablespoons of granulated sugar over the top if desired for a delicate crackly crust.
- Bake for about 60 minutes, or until a cake tester inserted into the loaf comes out clean. If the center is still underbaked after 60 minutes, tent loosely with foil and bake for another 10 to 15 minutes, checking regularly.
- Let the loaf cool in the pan briefly, then transfer to a wire rack. Some sinking in the middle is normal because of the lemon curd layers.
- Slice and enjoy warm, or cool completely before storing airtight.
Notes
Make the lemon curd before starting the loaf batter. Homemade or store-bought lemon curd both work, but the curd should be ready to layer as soon as the batter is mixed.
Use room-temperature eggs and softened butter so the batter blends smoothly. The sandy mixing step coats the flour with butter, helping create a rich, tender crumb. Beat the batter well after adding kefir or buttermilk so it becomes thick, fluffy, and able to support the lemon curd layers.
Kefir gives the loaf a tangy flavor and tender texture, but full-fat buttermilk works as a one-to-one substitute. Plain whole milk yogurt thinned with a splash of milk can also be used in a pinch.
Toss blueberries in a spoonful of flour before folding them into the batter to help prevent them from sinking. Frozen blueberries can be used, but do not thaw them first; add them straight from the freezer after tossing with flour.
Do not skip greasing, flouring, and lining the pan with parchment paper. This loaf is moist and heavy because of the lemon curd, so parchment helps prevent sticking.
Keep the top layer of the loaf as plain batter, with no lemon curd exposed, so the curd does not burn during baking. A little sinking in the middle after baking is normal because the curd adds moisture and weight.
If the loaf is undercooked in the center after 60 minutes, tent loosely with foil and continue baking for 10 to 15 minutes, checking with a cake tester. If the lemon curd sinks to the bottom, the batter may have been too thin; beat until genuinely thick and fluffy before layering.
For variations, swap blueberries with raspberries or blackberries, add a simple glaze after cooling, or use a streusel topping instead of the sugar sprinkle for extra crunch.
Store in an airtight container at room temperature for 2 to 3 days, refrigerated for up to 5 days, or frozen tightly wrapped for up to 2 months. Reheat slices in the microwave for 10 to 15 seconds to soften the curd. Thaw frozen loaf overnight on the counter before serving.
Use leftover lemon curd in yogurt, on toast, or as a pancake topping. Extra egg whites from homemade lemon curd can be used in meringue or another no-waste dessert.