Pour the apple cider in a small or medium sauce pan. Heat over medium heat to a gentle boil. Reduce the heat to a simmer. Cook until the cider has reduced to about 1/2 c of concentrated apple cider. This takes about 30-35 minutes. Remove from the heat to cool until warm, but not hot to the touch. This takes about 15 minutes. It is recommended to make this about 1 hour (up to 1-2 days) before using in the recipe. Preheat the oven to 375 F (190 C). Lightly spray a 24 ct. muffin pan or 12ct. regular muffin pan with non stick spray. Set aside.
Whisk the flours, spice, baking powder, baking soda and salt together until well combined.
Once the reduced apple cider has cooled to warm, pour this into a bowl with the room temperature sour cream and vanilla. Stir until well combined. Set aside.
Whisk the eggs and sugar together until pale yellow and frothy, about 2 minutes.
Slowly whisk in the melted butter. Whisk the eggs, sugar and melted butter until well combined and emulsified.
Alternate stirring in the dry ingredients with the apple cider/sour cream mixture into the wet in this order: dry, apple cider mixture, dry, apple cider mixture, dry. Stir until JUST combined with no flour streaks.
Using a small cookie scoop (about the size of a melon ball scooper) or small spoon for mini muffins or medium cookie scoop for regular muffins, fill each muffin well of the prepared muffin pan about half way to the top.
Bake the muffins in a 375F (190C) for:10-12 minutes for mini muffins18-22 minutes for regular muffinsThe edges will be set and golden brown. The tops of the muffins will dome, have slight cracks and a toothpick inserted in the center will yield a few moist crumbs.
Cool the muffins in the pan for 5 minutes.
Gently run a butter knife around the edges of the muffins to loosen them from the pan. Gently work each muffin out of the pan to cool on a cooling rack.