Preheat the oven to 350 degrees. Grease a 9x9 inch metal baking pan and line it with parchment paper.
In a medium bowl, combine the flour, cinnamon, nutmeg, allspice, baking powder, baking soda, and salt. Then set aside the flour mixture.
2 1/4 cups (282 g) all-purpose flour, spooned and leveled, 1 tbsp cinnamon, 1 tsp nutmeg, 1/4 tsp allspice, 1 1/2 tsp baking powder, 1/4 tsp baking soda, 1/2 tsp salt
Add the granulated white sugar, brown sugar and butter to a large bowl. Cream together for 2 minutes on high speed with an electric mixer. (You can also use the bowl of a stand mixer fit with a paddle attachment.)
10 tbsp (140 g) unsalted butter, softened, 1 cup (200 g) granulated white sugar, 1/2 cup (110 g) light brown sugar, packed
Then add in the eggs and vanilla and mix on medium speed until pale in color and smooth, about 1 minute.
3 eggs, at room temperature, 1 tbsp vanilla
Add in the buttermilk, sour cream, 1/2 cup of apple cider reduction, and apple butter. Mix on medium speed until combined. The batter will look curdled at this point but don't worry. It will pull together once the dry ingredients are added.
1/2 cup (120 ml) buttermilk, at room temperature, 1/2 cup (122 g) sour cream, at room temperature, 1/2 cup (120 ml) apple cider reduction from above, at room temperature, 1/3 cup (95 g) unsweetened apple butter, at room temperature
Add in the dry ingredients a little bit at a time, mixing on low speed just until all is combined and the batter is smooth. Scrape the sides of the bowl with a rubber spatula as necessary.
Pour the batter into the prepared pan. Bake the cake for 48-52 minutes, or until a toothpick comes out clean from the center.
Let the cake cool in the pan on a wire cooling rack until completely cool.