Persimmon Muffin

Preheat your oven to 190°C (375°F) with a rack positioned in the center. Line a 12-cup standard muffin tin with paper baking liners, or lightly coat each cup with non-stick cooking spray to prevent muffins from sticking during baking.

Peel the fully ripe, soft Hachiya persimmons, scoop out the gelatinous inner flesh, and discard any hard black seeds. Mash the flesh in a small glass bowl with a fork for 1 minute until completely smooth; you should have 240ml (1 cup) of uniform orange puree, set aside.

In a medium 2L mixing bowl, combine the 190g all-purpose flour, 5g baking soda, 2.6g ground cinnamon, 0.6g ground nutmeg, and 3g fine table salt. Whisk vigorously for 30 seconds to evenly distribute the leavening and spices, breaking up any small clumps.

In a separate large 3L mixing bowl, add the cooled melted 57g unsalted butter, 100g packed light brown sugar, 50g room-temperature egg, 5ml vanilla extract, and prepared persimmon puree. Whisk for 1 minute until the mixture is glossy, uniformly orange, with no visible streaks of unincorporated egg.

Pour the entire dry ingredient mixture into the bowl of wet ingredients. Fold gently with a silicone spatula for 20-25 seconds, just until no dry white flour streaks remain; the batter will be slightly lumpy. If using, fold in the 75g chopped walnuts in the final 3 folds, taking care not to overmix (overmixing creates tough muffins).

Scoop 3 tbsp (about 45ml) of batter into each lined muffin cup, filling each liner exactly 2/3 full to leave room for rising. Bake on the middle oven rack for 18-20 minutes at 190°C (375°F). Test doneness by inserting a wooden toothpick into the center of a middle muffin: it should come out with 1-2 moist crumbs, not wet batter.

Remove the baked muffin tin from the oven, and let muffins rest in the tin for 5 minutes to set, then transfer each muffin to a wire cooling rack to cool for an additional 10 minutes. Serve slightly warm, or store in an airtight container at room temperature for up to 3 days.