How to Make It
Preheat oven to 250°F. Heat milk and cream in a saucepan over medium-high until mixture just comes to a boil. Remove from heat; let cool slightly, about 10 minutes.
Meanwhile, whisk together egg yolks and 1/4 cup sugar in a bowl until smooth and pale, about 2 minutes. Whisk in chestnut spread until smooth.
Gradually whisk hot milk mixture into egg mixture until combined. Divide mixture evenly among 8 (6- to 8-ounce) ramekins. Place ramekins in a large roasting pan (or 2 [13- x 9-inch] baking pans), and carefully pour enough hot water into roasting pan to come halfway up sides of ramekins.
Carefully transfer pan to preheated oven. Bake until custard is set, 50 to 55 minutes. Remove ramekins from pan, and transfer to a wire rack. Let cool to room temperature, about 1 hour. Refrigerate until chilled, about 2 hours.
Sprinkle ramekins evenly with remaining 1/2 cup sugar. Using a kitchen torch, torch tops until sugar caramelizes.