Pour 2 cups of apple cider into a small saucepan. Bring to a boil over medium-high heat, then reduce heat to medium-low and simmer, stirring occasionally, until the cider has reduced to about 1/2 cup (this takes approximately 15-20 minutes). Remove from heat and let cool completely before using.

Preheat your oven to 350°F (175°C). Generously grease and flour a 10-12 cup bundt pan, ensuring all nooks and crannies are coated. Tap out any excess flour.

In a medium bowl, whisk together the sifted all-purpose flour, baking powder, baking soda, ground cinnamon, ground nutmeg, ground cloves (if using), and salt. Set aside.

In a large mixing bowl with an electric mixer (stand or hand-held), cream together the softened unsalted butter and granulated sugar on medium-high speed until light and fluffy, about 3-4 minutes. Scrape down the sides of the bowl as needed.

Add the eggs one at a time, beating well after each addition until fully incorporated. Beat in the sour cream and vanilla extract until just combined.

With the mixer on low speed, gradually add the dry ingredients to the wet ingredients, alternating with the cooled 1/2 cup of reduced apple cider, beginning and ending with the dry ingredients (e.g., 1/3 dry, 1/2 cider, 1/3 dry, 1/2 cider, 1/3 dry). Mix until just combined and no streaks of flour remain; be careful not to overmix.

Pour the batter evenly into the prepared bundt pan. Tap the pan gently on the counter a few times to release any air bubbles.

Bake for 50-55 minutes, or until a wooden skewer or toothpick inserted into the center of the cake comes out clean. The cake should be golden brown and spring back when lightly touched.

Remove the cake from the oven and let it cool in the pan on a wire rack for 10-15 minutes. This allows the cake to set before inverting.

While the cake is cooling, prepare the cinnamon sugar coating. In a small bowl, combine 1/2 cup granulated sugar and 2 tablespoons ground cinnamon. In a separate microwave-safe bowl, melt the 1/2 cup unsalted butter.

After the initial cooling time, carefully invert the bundt cake onto the wire rack. Place the wire rack over a baking sheet or parchment paper to catch any drips from the coating.

While the cake is still warm, brush the entire surface of the cake liberally with the melted butter. You can use a pastry brush or spoon it over. Once buttered, immediately sprinkle or spoon the cinnamon sugar mixture generously over the entire cake, rotating to ensure all sides are coated. Repeat with any remaining butter and cinnamon sugar until the cake is fully coated.

Let the cake cool completely on the wire rack before slicing and serving. This allows the coating to set and the flavors to fully meld.