Ingredients

1 teaspoon cornstarch

2 teaspoons lemon juice (or water)

1 cup (140g) fresh or frozen blueberries (do not thaw)

2 teaspoons granulated sugar

1/2 cup (8 Tbsp; 113g) unsalted butter, melted

1/4 cup (50g) granulated sugar

1 teaspoon pure vanilla extract

1/4 teaspoon salt

1 cup (125g) all-purpose flour (spooned & leveled)

1 (14 ounce) can full-fat sweetened condensed milk

6 Tablespoons (90ml) lemon juice (about 2 lemons)

1 teaspoon lemon zest (1 lemon)

1 large egg yolk

Lemon slices, blueberries, leftover blueberry sauce, whipped cream for garnish (optional)

Instructions

Step 1: Mix cornstarch and lemon juice (or water) in a small bowl until dissolved. In a small saucepan over medium heat, warm blueberries and 2 teaspoons sugar for 3 minutes, mashing the berries against the pan to break them up. Stir in the cornstarch mixture and cook for 2 more minutes until thickened, continuing to mash. Remove from heat and set aside to cool. This makes about 1/2 to 2/3 cup blueberry sauce; use half for the tart and reserve the rest for serving.

Step 2: Preheat oven to 350°F (177°C).

Step 3: In a medium bowl, combine melted butter, 1/4 cup sugar, vanilla extract, and salt. Add flour and stir until fully combined into a thick, slightly greasy dough.

Step 4: Press the dough evenly into a 9-inch tart pan, covering the bottom and sides. Use a spatula, your hands, or the bottom of a measuring cup to pack it in firmly.

Step 5: Bake crust for 15 minutes until edges are lightly browned. Remove and poke small holes all over the warm crust with a fork without piercing through.

Step 6: Whisk together sweetened condensed milk, lemon juice, lemon zest, and egg yolk until smooth. Pour filling into the warm crust.

Step 7: Stir the blueberry sauce to loosen it if thickened, warming briefly if needed. Drop spoonfuls evenly over the filling. Using a toothpick or knife, gently swirl the sauce into the filling. Gently shake the pan 2–3 times to settle the mixture.

Step 8: Bake for 17–19 minutes until the center no longer jiggles lightly when tapped but remains soft. Avoid over-baking to keep a creamy texture.

Step 9: Cool the tart completely on a rack, then chill uncovered in the refrigerator for at least 2 hours or up to 1 day (cover if chilling longer). Remove tart pan sides if removable before serving.

Step 10: Slice and serve, garnished with lemon slices, fresh blueberries, leftover blueberry sauce, or whipped cream if desired.

Tips & Variations

Use frozen blueberries straight from the freezer to prevent excess liquid in the sauce.

For a gluten-free option, substitute all-purpose flour with a gluten-free blend.

Swirling the blueberry sauce adds visual appeal and a fruity pop of flavor—avoid over-mixing to maintain pretty marbling.

Don’t over-bake the tart; a slightly soft center ensures a creamy, luscious texture after chilling.

FAQs

Can I make this tart ahead of time?

Yes, it can be assembled and chilled up to 1 day in advance, which helps the filling set nicely and enhances the flavors.

What can I use instead of sweetened condensed milk?

Sweetened condensed milk provides sweetness and creaminess that’s key to the filling. For a substitute, try a mixture of evaporated milk and sugar, but note the flavor and texture may differ slightly.