Banana Walnut Tartufo Recipe

Prepare bananas

Peel and roughly chop bananas. Toss with 1 tsp lemon juice to prevent browning. Puree in a blender or food processor until smooth (about 1 cup of banana purée).

Make custard base

In a medium saucepan, warm the whole milk and 1 cup heavy cream over medium heat until it steams but does not boil. In a separate bowl, whisk together the egg yolks, 3 tbsp granulated sugar and 2 tbsp brown sugar until pale and ribbon-like. Slowly temper about 1/3 of the hot milk mixture into the yolks while whisking, then pour the tempered yolk mixture back into the saucepan. Cook over medium-low heat, stirring constantly with a wooden spoon or spatula, until the mixture coats the back of the spoon (170–175°F / 77–80°C). Do not boil.

Finish custard

Remove custard from heat and strain through a fine-mesh sieve into a clean bowl. Stir in the remaining 1 cup heavy cream and 1 tsp vanilla extract. Whisk in the banana purée until fully incorporated. Chill the custard thoroughly in the refrigerator until cold, at least 2 hours (or overnight) to ensure proper churn consistency.

Churn and add walnuts

Churn the chilled banana custard in an ice cream maker according to manufacturer’s instructions until it reaches soft-serve consistency. During the last minute of churning, add the toasted chopped walnuts so they distribute evenly. Transfer churned ice cream to a container and freeze until firm, about 4 hours or overnight.

In a medium, heavy-bottomed saucepan, combine 1 cup granulated sugar and 3 tbsp water. Swirl the pan gently (do not stir) to moisten the sugar and cook over medium heat until the sugar dissolves and turns a deep amber color (watch carefully to prevent burning).

As soon as the caramel reaches a rich amber color, remove the pan from heat and carefully add 1 cup heavy cream in a slow stream while whisking (steam will rise). The caramel will bubble vigorously—keep whisking until smooth.

Stir in 4 tbsp unsalted butter until incorporated. Off the heat, whisk in 2 tbsp white miso paste until fully dissolved and the sauce is silky. Finish with 1 tsp sea salt. Taste and adjust: add a pinch more salt or 1/2 tsp miso if desired. Allow caramel to cool to room temperature; it will thicken as it cools.

Preheat oven to 225°F (110°C). Line two baking sheets with parchment paper.

In a completely clean, dry mixing bowl, combine 4 egg whites and 1 tsp cream of tartar. Using a hand or stand mixer with a whisk attachment, beat on medium speed until frothy. Gradually add 1 cup granulated sugar, about 1 tbsp at a time, increasing speed to high and beating until glossy, stiff peaks form and sugar is fully dissolved (rub a bit between fingers to check for grit). Beat in 1 tsp vanilla.

For tartufo, you need individual meringue domes that will encase the ice cream. Using a large spoon or piping bag fitted with a round tip, pipe or spoon domes roughly 3 inches (7–8 cm) across onto the prepared parchment. Make two layered domes for each tartufo: a base (concave to hold ice cream) and a hollow top (a dome with a small cavity) so the ice cream core can be enclosed. Smooth edges and sprinkle a little fine sugar on top if desired.

Bake at 225°F (110°C) for 60–75 minutes until dry and crisp to the touch. Turn the oven off and let meringues cool inside with the door slightly ajar for 1 hour to avoid cracking from rapid temperature change. Remove and cool completely.

Prepare ice cream cores: scoop or cut rounds of frozen banana walnut ice cream slightly smaller than the meringue base cavity. If ice cream is too firm, sit at room temperature for 3–5 minutes until scoopable, then re-freeze the shaped cores for 20–30 minutes to firm up.

Optional: Spread a thin layer (about 1 tsp) of melted dark chocolate inside the meringue base cavity and let set — this creates a moisture barrier so the meringue does not become soggy. Chill briefly to set chocolate.

Drizzle a teaspoon of cooled miso caramel into the chocolate-lined base, place the frozen ice cream core on top, then drizzle another teaspoon of miso caramel over the ice cream. Cap with the meringue dome top, pressing gently to seal. Repeat to assemble all tartufo. For extra security, brush a little melted dark chocolate around the join and let set.

Just before serving, brush or drizzle additional miso caramel over the assembled tartufo as desired. Using a small kitchen blowtorch, carefully torch the exterior meringue until lightly browned and caramelized in spots (keep flame moving and do not overheat the meringue). If you prefer, you can brown the meringue tops under a very hot broiler for 30–60 seconds—watch closely.

Garnish each tartufo with a sprinkle of extra toasted walnut pieces and a light dusting of powdered sugar if desired. Serve immediately.