01 - Preheat oven to 350°F. Thoroughly grease and flour a 10-cup bundt pan.
02 - Simmer apple cider over medium heat in a saucepan until reduced to 3/4 cup, about 15 minutes. Let cool.
03 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, nutmeg, allspice, and cloves.
04 - Using an electric mixer, cream butter with granulated and brown sugars until light and fluffy, approximately 3 to 4 minutes.
05 - Beat in the eggs one at a time, mixing well after each addition. Stir in sour cream and vanilla extract.
06 - Add the flour mixture in three parts, alternating with reduced apple cider, beginning and ending with the flour mixture. Mix until just combined.
07 - Gently fold diced apples into the batter.
08 - Pour batter evenly into prepared pan and smooth the top. Bake for 45 to 55 minutes or until a toothpick inserted in the center exits clean.
09 - Let the cake cool in the pan for 15 minutes, then invert onto a wire rack to cool completely.
10 - Whisk powdered sugar with apple cider until smooth and pourable. Drizzle over cooled cake before serving.