1. Preheat oven to 350°F (175°C) and grease a 12-cavity donut pan.

2. Pour 1 cup apple cider into a saucepan and simmer over medium heat until reduced to 1/2 cup, about 15 minutes. Let cool.

3. In a bowl whisk flour, baking powder, baking soda, cinnamon, and salt.

4. In another bowl whisk granulated sugar, brown sugar, eggs, melted butter, milk, reduced cider, and apple cider vinegar.

5. Gently fold wet ingredients into dry until just combined, then fold in diced apples.

6. Transfer batter to a piping bag or zip-top bag and fill each donut cavity two-thirds full.

7. Bake donuts 10–12 minutes or until a toothpick comes out clean. Let cool in pan 5 minutes, then transfer to a rack.

8. Toss warm donuts in cinnamon sugar or drizzle with glaze made by mixing powdered sugar and a few tablespoons reduced cider.

9. For fritters, spoon batter into greased muffin tin or drop by spoonfuls onto a parchment-lined sheet.

10. Bake fritters 13–15 minutes until golden and crisp. Optionally fry in 350°F oil 2–3 minutes per side, then drain on paper towels.

11. Serve donuts and fritters warm, dusted with sugar or drizzled with cider glaze.