Ingredients:

  • 4 large (about 1.8 kg / 4 lbs total) Sweet Potatoes (Yams), peeled
  • 1 tbsp Unsalted Butter, softened (for greasing the dish)
  • 5 cups (360 ml) Heavy Cream (Double Cream)
  • 5 cup (120 ml) Whole Milk (Full-fat milk)
  • 5 cup (120 ml) Pure Maple Syrup
  • 2 tbsp Light Brown Sugar, packed
  • 1 tsp Vanilla Extract
  • 1 tsp Ground Cinnamon
  • 5 tsp Ground Nutmeg
  • 5 tsp Kosher Salt
  • Pinch of Freshly Ground Black Pepper
  • 75 cup (100g) Dried Cranberries
  • 5 cup (60g) All-Purpose Flour
  • 5 cup (50g) Pecans, roughly chopped
  • 33 cup (75g) Light Brown Sugar, packed
  • 4 tbsp (56g) Cold Unsalted Butter, cut into small cubes

Instructions:

  1. Prep and Preheat: Preheat oven to 375°F (190°C). Grease a 9x13 inch baking dish thoroughly with softened butter. Peel sweet potatoes, and using a mandoline or sharp knife, slice the potatoes into uniform rounds, approximately 1/8 inch (3mm) thick. Set aside.
  2. Prepare the Pecan Crunch Topping: In a small bowl, combine the flour, chopped pecans, and brown sugar. Cut in the cold butter using your fingertips or a pastry blender until the mixture resembles coarse, pea-sized crumbs. Place the topping in the refrigerator.
  3. Create the Cream Sauce: In a medium saucepan, gently warm the heavy cream and milk until just steaming. Remove from heat and whisk in the maple syrup, brown sugar, vanilla extract, cinnamon, nutmeg, salt, and pepper until the sugar is fully dissolved.
  4. Layer the Gratin (First Layer): Arrange one-third of the sliced sweet potatoes in an overlapping, tight pattern across the bottom of the prepared baking dish. Sprinkle half of the dried cranberries evenly over the potato layer. Carefully pour one-third of the cream sauce evenly over the layers.
  5. Layer the Gratin (Second and Third Layers): Repeat the process: Add the second layer of potatoes, sprinkle the remaining cranberries, and pour the second one-third of the cream sauce. Top with the final layer of sweet potatoes and pour the remaining cream sauce over the top, tilting the dish slightly to ensure the sauce penetrates all the edges.
  6. Bake Covered: Tightly cover the baking dish with foil. Bake for 30 minutes at 375°F (190°C).
  7. Bake Uncovered: Remove the foil. Sprinkle the chilled Pecan Crunch Topping evenly over the surface. Return to the oven and bake uncovered for an additional 20–25 minutes, or until the topping is golden brown and bubbling, and the potatoes are fork-tender.
  8. Rest and Serve: Remove the gratin from the oven. Let it rest on the counter for 10 minutes before serving. This resting period allows the sauce to thicken and the layers to set properly.