Moist, tender muffins bursting with layered apple flavor from reduced cider, applesauce, and shredded apple, warmly perfumed with cinnamon and baking spices. Finished with a buttery cinnamon-sugar coat for classic apple-cider-donut vibes.
Reduce the cider: In a small saucepan, simmer 3/4 cup (180 ml) fresh apple cider over medium heat, stirring occasionally, until reduced to 1/4 cup (60 ml), about 20 minutes. Cool to room temperature.
Preheat the oven to 425°F (218°C). Line or grease a 12-count muffin pan.
Whisk dry ingredients: In a large bowl combine flour, baking powder, baking soda, salt, cinnamon, allspice, cloves, and nutmeg.
Whisk wet ingredients: In a medium bowl whisk oil, brown sugar, granulated sugar, eggs, applesauce, and the cooled reduced apple cider until smooth.
Combine: Pour wet ingredients into dry ingredients and whisk just until combined. Fold in shredded apple and walnuts (if using).
Portion: Divide batter evenly among 12 muffin cups, filling each to the top.
Bake: Bake 5 minutes at 425°F (218°C), then reduce oven to 350°F (177°C) and bake 15–16 minutes more, until a toothpick comes out clean.
Cool: Let muffins cool in the pan on a rack for 10 minutes, then transfer to the rack.
Topping: Mix granulated sugar and cinnamon in a bowl. Brush tops of warm muffins with melted butter, then dip tops (or roll entire muffin) in cinnamon-sugar to coat.
Storage: Cover lightly and store at room temperature up to 3 days or refrigerate up to 1 week. Freeze up to 3 months; thaw overnight in the refrigerator.