Step 1

Make the malabi: Whisk together 1 cup (240 ml) of the milk and the cornstarch until the cornstarch fully dissolves; set aside.

Step 2

Whisk together the remaining 3 cups (720 ml) milk and the sugar in a medium saucepan. Set over medium heat and bring to a simmer, whisking often. Add the cornstarch-milk mixture and cook, whisking constantly, until the mixture thickens to the consistency of loose pudding, 3-5 minutes. Remove from the heat and whisk in the vanilla. Divide the mixture evenly among six small serving bowls and let cool to room temperature. Cover with plastic wrap and refrigerate until chilled, at least 4 hours.

Step 3

Make the caramel: Stir together the sugar and water in a medium saucepan, and set over medium-high heat. Cook (do not stir) until the sugar turns a deep amber color, about 10 minutes. Carefully add the butter (it will cause the sugar to bubble up) and salt, and stir to combine. Slowly whisk in the cream and continue to cook, whisking often, until the caramel is smooth and thickened, 2-3 minutes. Remove from the heat and let cool slightly.

Step 4

Just before serving, drizzle caramel over each malabi cup (reserving the remaining caramel for another use) and sprinkle with peanuts. Serve cold.