Preheat oven to 400°F (200°C). Line a rimmed quarter sheet pan with foil.

Place mango and pineapple on prepared pan. In a small bowl, whisk together 2 tablespoons (42 grams) honey, orange juice, melted butter, and ½ tablespoon (9 grams) vanilla bean paste. Brush fruit with half of honey mixture.

Bake for 30 minutes. Brush with remaining honey mixture, and bake 10 minutes more. Let cool slightly.

In the container of a blender, place roasted mango pieces; process until smooth. Measure 2 cups (480 grams) purée. In same container, place roasted pineapple and any remaining juice from pan; process until smooth. Measure ½ cup (130 grams) purée.

Return both purées to container, and process until combined. Add sugars, ginger, remaining ¼ cup (85 grams) honey, and remaining 1 tablespoon (18 grams) vanilla bean paste; process until smooth and uniform in color. Add buttermilk, blending to combine. Blend in flour and salt.

Preheat oven to 425°F (220°C).

Roll chilled Vanilla Bean Piecrust dough to 3⁄16-inch thickness, about 15 inches in diameter. Transfer to a 9-inch deep-dish glass pie plate, pressing into bottom and completely up sides. Trim excess dough to ½ inch beyond edge of plate. Fold edges under, and crimp as desired. Prick dough all over with a fork. Top with a piece of parchment paper, letting ends extend over edges of plate. Add pie weights.

Bake for 15 minutes. Carefully remove paper and weights. Bake until crust looks dry, about 5 minutes more. Remove from oven. Reduce oven temperature to 325°F (170°C).

In a large saucepan, heat purée mixture over medium-low heat until steaming. In a large bowl, whisk eggs. Carefully add half of hot purée mixture to eggs, whisking constantly. Return mixture to saucepan. Cook, stirring constantly, until mixture starts to thicken and an instant-read thermometer registers 160°F (71°C).

Press mixture through a fine-mesh sieve, discarding solids. Add softened butter, a few pieces at a time, stirring slowly with a spatula until combined after each addition. Pour filling into warm crust.

Bake until edges are set but center still jiggles slightly and an instant-read thermometer registers 175°F (79°C) to 180°F (82°C), about 55 minutes. Let cool to room temperature. Cover and refrigerate for at least 4 hours or overnight. Serve with mango, pineapple, and whipped cream.