Step 1: Prepare the Egg Yolk Mixture

1. In a large mixing bowl, whisk together 3 large egg yolks and 70 g granulated sugar until combined.
2. Create a double boiler: Fill a small pot with 1 inch of water and bring to a boil. Turn off the heat and place the mixing bowl over the pot (ensure the bowl doesn’t touch the water).
3. Whisk the egg yolk mixture over the double boiler until the sugar dissolves and the mixture becomes warm, fluffy, and pale, about 5–7 minutes. Remove from the pot.

Tip: Whisk constantly to prevent curdling; the mixture should be warm but not cooked.

Step 2: Add Mascarpone

1. Immediately add 225 g softened mascarpone cheese to the warm egg mixture.
2. Whisk until the mascarpone melts completely and the mixture is smooth with no lumps. Set aside.

Tip: Ensure mascarpone is at room temperature for easy blending; whisk thoroughly to avoid lumps.

Step 3: Whip the Cream

1. In another large mixing bowl, combine 350 g whipping cream and 1 tsp vanilla extract.
2. Use an electric hand mixer to beat until firm peaks form (3–5 minutes).

Tip: Use cold cream for best whipping; stop when peaks hold shape to avoid over-beating.

Step 4: Combine Cream and Mascarpone Mixture

1. Gently fold the whipped cream into the mascarpone mixture with a spatula until no streaks remain.

Tip: Fold in a figure-eight motion to maintain airiness; avoid overmixing to keep the cream light.

Step 5: Prepare the Soak

1. In a wide, shallow bowl, stir together 150 g mango juice and 2 oz dark rum.

Tip: Use a shallow bowl for easy dipping; stir well to combine flavors.

Step 6: Assemble the Tiramisu

1. Briefly dip each of the 30 ladyfingers (1 second per side) into the mango juice-rum mixture to coat both sides.
2. Arrange half the soaked ladyfingers in an even layer in a 9×9-inch dish or individual containers.
3. Spread half the mascarpone cream over the ladyfingers, smoothing with a spatula.
4. Add a layer of diced mangoes (from 3 small mangoes) and press gently into the cream.
5. Repeat with another layer of soaked ladyfingers and the remaining mascarpone cream, smoothing the top with a spatula or bench scraper for a flat surface.
6. (Optional) Transfer some mascarpone cream to a piping bag with an open star tip and pipe decorative swirls on top. Garnish with extra mango chunks.

Tip: Dip ladyfingers quickly to avoid sogginess; layer evenly for balanced bites.

Step 7: Chill and Serve

1. Cover and chill the tiramisu in the refrigerator for at least 6 hours, preferably overnight.
2. Serve cold, garnished with additional mango chunks if desired.

Tip: Chill thoroughly for set layers; use a sharp knife for clean slices if cutting.