Start by preheating your oven to 350 degrees, then prepare a 9x9 inch metal baking pan by greasing it and lining with parchment paper.
Combine 2 ¼ cups of all-purpose flour (282 g), 1 tablespoon of cinnamon, 1 teaspoon of nutmeg, ¼ teaspoon of allspice, 1 ½ teaspoons of baking powder, ¼ teaspoon of baking soda, and ½ teaspoon of salt in a medium bowl.
In a large bowl, blend granulated white sugar, brown sugar, and butter. Whip together at high speed using an electric mixer for 2 minutes. You may also opt for a stand mixer equipped with a paddle attachment.
Afterward, incorporate the eggs and vanilla, then mix at a medium speed for approximately 1 minute until the mixture turns pale in color and achieves a smooth consistency.
Incorporate buttermilk, sour cream, ½ cup of apple cider reduction, and apple butter into the mix. Blend at medium speed until fully combined. Don't be concerned if the batter looks curdled at this stage; it will unify once the dry ingredients are introduced.
To achieve a smooth batter, gently incorporate the dry ingredients little by little while mixing at a low speed. Ensure to scrape the sides of the bowl as necessary with a rubber spatula.
Begin by pouring the batter into the prepared pan, then bake the cake for 48-52 minutes. Check for doneness with a toothpick in the center.
Allow the cake to cool completely in the pan on a wire rack.