Lemon Posset Tart with Poppy Seed Shortbread Crust

Why You’ll Love This Recipe

• Ultra-silky lemon posset filling that sets without eggs or gelatin.
• Buttery poppy-seed shortbread crust adds crunch, nuttiness, and visual pop.
• Bright, clean citrus flavor balanced by gentle creaminess.
• Make-ahead friendly and slices beautifully for gatherings.

Grocery List

• Produce: 4–5 lemons (you’ll need zest and 1/2 cup juice)
• Dairy: 2 1/2 cups heavy cream; 10 tbsp unsalted butter
• Pantry: All-purpose flour, powdered sugar, granulated sugar, cornstarch, poppy seeds, vanilla extract, fine sea salt, optional white chocolate

Full Ingredients

Poppy-Seed Shortbread Crust

• 1 1/2 cups (180 g) all-purpose flour
• 1/2 cup (60 g) powdered sugar
• 2 tbsp (16 g) cornstarch
• 1/4 tsp fine sea salt
• 1 tbsp poppy seeds
• 10 tbsp (140 g) unsalted butter, melted and slightly cooled
• 1 tsp finely grated lemon zest (from about 1 lemon)
• 1/2 tsp vanilla extract
• Optional barrier: 1 oz (28 g) white chocolate, finely chopped

Lemon Posset Filling

• 2 1/2 cups (600 ml) heavy cream
• 3/4 cup (150 g) granulated sugar
• 1 tbsp finely grated lemon zest (from 2–3 lemons)
• 1/2 cup (120 ml) freshly squeezed lemon juice (strain out seeds/pulp)
• Pinch (about 1/8 tsp) fine sea salt
• Optional: 1/2 tsp vanilla extract

To Finish

• 1–2 tbsp powdered sugar, for dusting
• Finely grated zest from 1 lemon, for a fresh “shower” on top
• Additional poppy seeds, a pinch, optional

Step-by-Step Instructions

Step 1: Prep the pan and preheat

Heat the oven to 350°F (175°C) with a rack in the middle. Lightly butter a 9-inch (23 cm) tart pan with a removable bottom. If your pan tends to stick, cut a round of parchment to fit the base.

Step 2: Make the poppy-seed shortbread dough

In a medium bowl, whisk together the flour, powdered sugar, cornstarch, salt, and poppy seeds. Add the melted butter, lemon zest, and vanilla. Stir with a fork until the mixture forms evenly moistened crumbs and then a soft dough. It should hold together when pressed.

Step 3: Press, chill, and bake the crust

Tip the dough into the prepared pan and press it evenly across the base and up the sides (use the flat bottom of a measuring cup for a smooth, even layer). Dock the base with a fork 8–10 times. Freeze the crust for 15 minutes to minimize shrinkage.

Bake for 18–22 minutes, until the edges are lightly golden and the surface looks dry and set. Cool on a rack for 10–15 minutes. Optional moisture barrier: melt the white chocolate in short bursts in the microwave, then brush a thin layer over the warm crust; let set.

Step 4: Cook the lemon posset

In a medium stainless-steel saucepan, combine the heavy cream, granulated sugar, lemon zest, and a pinch of salt. Bring to a vigorous boil over medium-high heat, stirring frequently to prevent scorching and to dissolve the sugar. Once boiling, reduce to maintain a strong simmer and cook for exactly 3 minutes. Watch closely to avoid boil-overs.

Remove from heat. Whisk in the lemon juice (and vanilla, if using) until smooth. The mixture will thicken slightly as the acid hits the cream.

Step 5: Rest, strain, and pour

Let the posset rest off the heat for 5 minutes to settle. Strain through a fine-mesh sieve into a heatproof pitcher to remove zest and any stray bubbles. Slowly pour the filling into the cooled crust, right to the top but without overflowing.

Step 6: Chill until set

Chill the tart uncovered for 30 minutes to cool the surface, then cover loosely and refrigerate until fully set, at least 4 hours (overnight is ideal). The center should wiggle slightly but not slosh.

Step 7: Finish and serve

Right before serving, unmold the tart by pushing up the removable base. Dust the top lightly with powdered sugar and shower with fresh lemon zest. For the neatest slices, dip a sharp knife in hot water, wipe dry, and cut, repeating between slices. Serve chilled.

Pro Tips

• Use freshly squeezed lemon juice for clean, bright flavor and reliable setting; bottled juices vary in acidity.
• Keep the cream at a strong simmer for a full 3 minutes—this slight reduction helps the posset set sliceably.
• Straining is key for a glassy-smooth texture; it removes zest and any foam.
• For a crisper crust on day two, include the optional thin white-chocolate barrier.
• Microplane the zest very finely so you get perfumed oils without bitter pith.

Variations

• Lime Posset Tart: Swap lemon zest/juice with lime. Garnish with lime zest and a sprinkle of toasted coconut.
• Berry Swirl: Spoon 2–3 tablespoons of sieved raspberry coulis onto the poured posset and feather it with a toothpick before chilling.
• Almond-Sesame Crust: Replace poppy seeds with 2 tsp toasted sesame seeds and add 1/4 tsp almond extract.

Storage & Make-Ahead

The tart keeps, covered and refrigerated, for up to 3 days. The crust can be baked 1 day ahead (store airtight at room temperature); add the white-chocolate barrier for best crispness if assembling ahead. The finished tart does not freeze well due to the cream-based filling.

Nutrition (per serving)

Approximate values per slice (1/10 tart): 460 calories; 31 g fat (19 g saturated); 38 g carbohydrates; 3 g protein; 0.5 g fiber; 165 mg sodium. Values will vary with ingredient brands and optional white chocolate.