Blueberry Basil Tart Recipe

Prepare and bake cake

Preheat oven to 350°F (175°C). Grease and line the bottom of a 9-inch tart pan (with removable bottom) or a 9-inch round cake pan. In a medium bowl whisk together flour, baking powder and salt; set aside. In a large bowl or stand mixer, cream the softened butter and 3/4 cup granulated sugar until pale and fluffy (about 2–3 minutes). Add eggs one at a time, mixing until combined. Mix in lemon zest, lemon juice and vanilla. With the mixer on low, add the dry ingredients in two additions alternating with the 1/2 cup milk, beginning and ending with flour. Scrape bowl and mix until just combined—do not overmix. Spread batter evenly into prepared pan (batter will be relatively thin). Bake 20–25 minutes until a toothpick in center comes out clean and top is light golden. Let cool completely in pan on a wire rack. If using removable-bottom tart pan, trim cake to fit tart ring if necessary; you want a flat, even base about 3/4 inch thick. Transfer to serving plate or tart stand.

Make blueberry puree and bloom gelatin

Place blueberries, 1/2 cup sugar, and 1 tablespoon lemon juice in a medium saucepan over medium heat. Cook, stirring, until blueberries break down and release juices, about 6–8 minutes. Meanwhile sprinkle 1.5 tsp gelatin over 2 tablespoons cold water in a small bowl and allow to bloom for 5 minutes.

Finish gel

Remove saucepan from heat. Use an immersion blender (or transfer to blender) to puree the blueberry mixture until smooth. Pour a small amount (2–3 tablespoons) of hot puree into the bloomed gelatin and whisk until dissolved; then whisk gelatin mixture back into remaining puree. Add salt and taste; if too tart, add up to 1 tablespoon more sugar. Strain puree through a fine mesh sieve to remove skins and seeds for a glossy gel. Let cool to warm (about 100–120°F / 38–49°C) but not set.

Assemble gel on cake

If the lemon cake base is slightly domed, trim to make it flat. Pour 3/4 to 1 cup of the cooled blueberry gel into the center of the cake and gently spread, leaving a small border (so mousse will sit on the edges). Chill in refrigerator until gel is just set, about 20–30 minutes. Reserve any extra gel for garnish or serving.

Infuse basil into cream

Roughly chop basil leaves and place in a small saucepan with 1 cup heavy cream and 1/4 cup milk. Warm gently over medium-low heat until just below simmer (bubbles form at edges) then remove from heat. Cover and steep for 20 minutes to infuse basil flavor.

Strain and prepare gelatin

After steeping, strain cream through a fine sieve, pressing on leaves to extract as much liquid as possible. Rewarm the infused cream gently. Meanwhile bloom 1.5 tsp gelatin in 2 tablespoons cold water for 5 minutes.

Make custard base

In a heatproof bowl, whisk together 3 egg yolks and 1/4 cup sugar until pale. Slowly temper the warm basil-infused cream into the yolks (drizzle while whisking) until combined. Return mixture to saucepan and cook over low heat, stirring constantly, until it thickens slightly and coats the back of a spoon (do not boil). Remove from heat, stir in bloomed gelatin until dissolved, then stir in lemon zest and 1/8 tsp salt. Let mixture cool to room temperature, stirring occasionally so it does not skin.

Whip cream and fold

Whip 1 cup heavy cream to soft peaks with about 1 tablespoon sugar (reserve from sugar amounts) and gently fold whipped cream into the cooled basil custard until fully combined and airy. Taste and adjust sweetness or basil level if necessary. Chill mousse briefly if needed until it is pipeable (15–20 minutes).

Pipe mousse onto tart

Pipe or spread basil mousse around the blueberry gel layer, creating a ring or decorative pattern. Smooth or texture as desired. Chill the assembled tart in refrigerator for at least 2 hours to set the mousse fully (preferably 3–4 hours or overnight).

Candy basil leaves

Make a light sugar syrup by combining 1/4 cup water and 1/2 cup granulated sugar in a small saucepan. Heat until sugar dissolves and syrup is clear; bring to a gentle simmer for 1 minute then remove from heat and let cool slightly. Using tongs, briefly dip individual basil leaves into syrup (coating both sides) and then immediately dredge or sprinkle with granulated sugar to coat. Place leaves on parchment to dry for at least 30 minutes until crisp. Optionally dust with a little powdered sugar before using.

Finish and serve

When mousse is set and blueberry gel is firm, arrange extra fresh blueberries on top or around the gel center. Place candied basil leaves on top for an aromatic, crisp garnish. If you reserved extra blueberry gel, warm it slightly and spoon small dots around the tart edge or make a glossy drizzle. Chill briefly, then slice with a hot, clean knife for neat slices. Serve cold; keeps 2–3 days refrigerated (candied basil best the first day).