Preheat your oven to 425°F (218°C). Grease and add a sprinkle of sugar to every other cup in a 12-cup muffin tin; this recipe makes 6 muffins, and spacing them out allows for better air circulation and helps them rise taller. For this recipe, avoid using muffin liners, as you'll be rolling the muffins in cinnamon sugar after baking.
To reduce the apple cider, you can use either the microwave or the stovetop.
Microwave Method: In a 2-cup glass measuring cup or bowl, cover the cider with plastic wrap, making sure to poke holes for venting. Heat it on high for 8 to 10 minutes, or until it reduces to about 1/2 cup (118 ml).
Stovetop Method: Pour the apple cider into a saucepan and heat over medium heat. Stir occasionally until it reaches a gentle boil. Then, let it simmer, stirring every minute or so, for about 10 minutes, or until it’s reduced by half.
After reducing the cider, whisk in the butter until it melts and blends smoothly. Let the mixture cool for a few minutes; it will have a slightly syrupy consistency. You’ll need 1/2 cup (118 ml) of this cider-butter mixture for the muffin batter and 2 tablespoons (30 ml) for the glaze.
In a large bowl, combine 1/2 cup (118 ml) of the reduced cider-butter mixture with sugar, egg, yogurt, and vanilla. Whisk everything together until well mixed.
In a separate medium bowl, mix the dry ingredients: flour, cinnamon, nutmeg, cloves, salt, baking soda, and baking powder.
Pour the dry ingredients into the bowl with the wet ingredients and gently stir with a large spoon or spatula until just combined. Make sure there are no large pockets of flour, but be careful not to overmix, as this can make the muffins tough, and nobody wants that!
Fill each of the 6 muffin cups with batter, using a 1/4 cup ice cream scoop for even portions. Bake at 425°F (218°C) for 5 minutes. Without opening the oven door, lower the temperature to 350°F (180°C) and continue baking for another 10-15 minutes. The muffins are done when they’re puffed up and firm. To check, insert a toothpick in the center; it should come out clean or with a few crumbs.