Blueberry & Poppyseed Lemon Bars 

Makes 9 large or 16 small bars

I’ve loved lemon bars ever since I was a kid. That contrast of buttery shortbread and silky, tart lemon curd is hard to beat. But I started wondering… what if I could take that classic and dress it up with two of lemon’s best pairings: poppyseed and blueberry?

The base stays true to tradition, with a tender shortbread crust studded with poppyseeds for a subtle crunch. On top, a layer of blueberry curd adds a light sweetness and a hint of vanilla that rounds out the tart lemon layer above.

I wasn’t entirely sure this clean, two-toned look would work, but after some testing, I landed on a method that delivers every time. The blueberry layer is baked first and allowed to set slightly before adding the lemon curd and finishing the bake. The result is perfectly defined, silky layers that taste just as good as they look.

Note: These bars require at least 4 hours of chill time, though overnight is best, so plan accordingly. This recipe can also be made in a 9×9-inch pan for slightly thinner bars—see notes for adjusted bake times.

WHAT YOU’LL NEED

INGREDIENTS

Poppyseed Shortbread Crust

  • 1 cup all-purpose flour (125 g)

  • ¼ cup granulated sugar (50 g)

  • ½ tsp kosher salt

  • 1 ½ tbsp poppy seeds

  • 8 tbsp unsalted butter, softened (113 g)

Blueberry Curd

  • 1 ¾ cups frozen blueberries (or sub fresh) (250 g)

  • Zest of 1 lemon

  • ¼ cup lemon juice (60 g)

  • ¾ cup granulated sugar (150 g)

  • 1 ½ tsp cornstarch

  • ¼ tsp kosher salt

  • 3 large eggs

  • 2 egg yolks

  • 4 tbsp unsalted butter, cut into pieces (56 g)

  • ½ tsp vanilla extract

Lemon Curd

  • ¾ cup granulated sugar (150 g)

  • ¼ tsp kosher salt

  • 1 tsp cornstarch

  • 3 large eggs

  • 1 egg yolk

  • 2 tsp lemon zest (from about 2 lemons)

  • ½ cup lemon juice (120 g)

  • 4 tbsp unsalted butter, cut into pieces (56 g)

Topping

  • ½ cup powdered sugar, for dusting

  • Optional: 2 tbsp freeze-dried blueberry powder (blitzed & sifted freeze-dried blueberries)

DIRECTIONS

Make the Poppyseed Shortbread Crust

  1. Preheat oven to 350°F (175°C). Line an 8x8 pan with parchment paper, leaving overhang on two sides so you can pull out the bars.

  2. In a medium bowl, mix together the flour, sugar, salt, and poppy seeds.

  3. Add the softened butter in pieces, using your fingers to pinch and rub it into the flour mixture until no dry spots remain, no large pieces of butter remain, and the mixture is uniformly crumbly.

  4. Transfer the mixture to the prepared baking pan and press into an even layer across the bottom.

  5. Bake for 13–15 minutes, until the edges are lightly golden and the center is set but pale.

  6. Reduce oven to 325°F (165°C) before proceeding.

Make the Blueberry Curd

  1. In a small saucepan, cook the blueberries, zest, and lemon juice over medium-low heat until the berries are fully broken down and the mixture is very juicy, about 10 minutes.

  2. Strain through a fine mesh sieve set over a bowl, pressing well with a spatula to extract as much liquid as possible. You should ideally have 100–130g of juice. Cool for 5–10 minutes.

  3. In a separate bowl, whisk together the sugar, cornstarch, and salt. Add the eggs and yolks, whisking until smooth.

  4. Whisk in the cooled blueberry mixture and return everything to the saucepan over medium-low heat.

  5. Cook, whisking continuously but gently (avoid incorporating air), until the mixture is thick enough to coat the back of a spoon, about 5–8 minutes.

  6. Turn off the heat and stir in the butter and vanilla until fully melted.

  7. Strain the curd through a fine mesh sieve into a bowl, pressing through with a spatula. (This step ensures a smooth, silky curd.)

  8. Pour into the crust, smoothing to the corners with an offset spatula. Lightly tap the pan to release air bubbles.

  9. Bake at 325°F for 13–15 minutes, until the edges are set and the center jiggles slowly when the pan is gently shaken.

  10. Cool at room temperature for 15-20 minutes.

Make the Lemon Curd

  1. In a small saucepan, whisk together the sugar, salt, and cornstarch.

  2. Add the eggs and egg yolk and mix until smooth. Then, stir in the lemon zest and juice.

  3. Place over medium-low heat, whisking continuously (but gently) until thickened, about 5–7 minutes.

  4. Turn off the heat and stir in the butter until fully melted.

  5. Strain through a fine mesh sieve into a bowl, pressing through with a spatula.

  6. Pour gently over the blueberry layer, smoothing evenly to the edges. Lightly tap the pan to release air bubbles.

  7. Bake at 325°F for 12–14 minutes, until edges are set and the center slightly jiggles.

  8. Cool to room temperature, then refrigerate for at least 4 hours, or preferably overnight.

  9. Lift out using the parchment overhang. Slice with a hot, clean knife into 9 large or 16 small squares. Dust with powdered sugar, optionally mixed with freeze-dried blueberry powder.

RECIPE NOTES & TIPS

  • These bars are an excellent make-ahead dessert and keep very well in the refrigerator for up to 4 days. Store in an airtight container for best texture and freshness.

  • If using a 9x9-inch pan instead of an 8x8, reduce the bake times slightly—by about 1–2 minutes per layer. The bars will be a bit thinner but will bake up just as nicely.

  • For a super silky lemon and blueberry curd, don’t skip straining. It makes a noticeable difference in achieving a smooth texture. Without straining, the curd may still taste delicious but can contain small bits of cooked egg and air bubbles, resulting in a less polished finish.

  • As the curd cooks, whisk slowly and gently, keeping the mixture moving without incorporating excess air. Vigorous whisking can introduce bubbles, which carry through to the final texture.

  • To create the two-toned finish, place a small piece of folded parchment paper diagonally over each bar. Dust exposed half with powdered sugar (optionally mixed with blueberry powder), then carefully lift the parchment to reveal a clean, sharp contrast.

  • To be precise and consistent when baking, I recommend using a Digital Food Scale. The one I linked is relatively inexpensive and in my opinion, a great investment for any home kitchen! But if you don’t have one, I’ll always include cup measurements as well.