In a large bowl, whisk together 1.5 cups all-purpose flour, 2 tablespoons granulated sugar, and 1/2 teaspoon salt. Add 6 tablespoons cold cubed unsalted butter. Using a pastry cutter or your fingers, cut the butter into the flour until mixture resembles coarse crumbs with some pea-sized pieces.

Bring dough together

Stir in 1/2 teaspoon vanilla extract. Sprinkle 1 tablespoon of ice water over the mixture and toss with a fork. Add remaining 2 tablespoons ice water, 1 tablespoon at a time, just until the dough begins to come together when pressed (do not overwork).

Chill and roll

Form the dough into a flat disc, wrap in plastic, and chill in the refrigerator for at least 30 minutes. Preheat oven to 375°F (190°C) while dough chills. On a lightly floured surface, roll the chilled dough to a 12-inch circle about 1/8-inch thick and fit into a 9-inch tart or pie pan, trimming the excess and crimping edges. Prick the bottom lightly with a fork.

Blind bake

Line the crust with parchment and fill with pie weights or dried beans. Bake for 15 minutes. Remove weights and parchment and bake 6–8 minutes more until the crust is golden and set. Let cool on a wire rack.

Blueberry Cream Filling

Prepare blueberries and corn

Place 2 cups fresh blueberries in a medium bowl. Measure 3 tablespoons corn kernels and set aside. For a smoother corn presence, pulse the corn once or twice in a food processor or chop finely; it should remain visible but not create large kernels in the filling.

Beat cream cheese

In a stand mixer or with a hand mixer, beat 8 ounces softened cream cheese on medium speed until smooth and lump-free, about 1–2 minutes.

Add sweeteners and dairy

Add 3/4 cup powdered sugar and 1/4 teaspoon salt to the cream cheese and beat until incorporated. Pour in 1/2 cup heavy cream, 1/4 cup sour cream, 1 teaspoon vanilla extract, 1 teaspoon lemon zest, and 1 tablespoon lemon juice. Beat on medium-high until the mixture is smooth and slightly thickened, about 1–2 minutes. The filling should be creamy but pipeable.

Fold in corn and blueberries

Using a spatula, gently fold the prepared corn kernels into the cream cheese mixture until evenly distributed. Then fold in the 2 cups fresh blueberries, stirring just enough to distribute them without breaking them up too much.

Assemble filling

Spoon the blueberry-cream mixture into the cooled baked crust, smoothing the top with an offset spatula. Tap the pan lightly on the counter to settle the filling and remove any air pockets.

Chill to set

Cover the tart loosely with plastic wrap and chill in the refrigerator at least 3 hours, preferably overnight, until the filling is firm to the touch and flavors meld.

Topping & Garnish

Finish and serve

Just before serving, spread or pipe 1/2 cup whipped cream over the tart or add dollops around the edge. Arrange 1/2 cup fresh blueberries on top. Dust lightly with 1 teaspoon powdered sugar and garnish with mint leaves if using. Slice with a sharp knife dipped in hot water and wiped dry between cuts for clean slices.