Preheat your oven to 350°F (175°C) and prepare a mini muffin pan by greasing it lightly.

In a medium saucepan, bring 1 cup of apple cider to a boil over medium-high heat. Simmer for 10-15 minutes until reduced to 1/2 cup.

In a large mixing bowl, whisk together the cooled apple cider mixture, eggs, apple butter, maple syrup, and vanilla extract until smooth.

In another bowl, combine all-purpose flour, whole wheat flour, baking powder, baking soda, ground cinnamon, ground cardamom, ground ginger, grated nutmeg, and kosher salt. Whisk until evenly mixed, then add to the wet ingredients and stir until just combined.

Pour the batter into the prepared mini muffin pan, filling each cavity about 1/2 to 2/3 full. Tap the pan to release air bubbles.

Bake for 10-12 minutes until the tops spring back and a toothpick inserted comes out clean. Keep an eye on them.

Once baked, cool for about 5 minutes on a wire rack, then gently run a butter knife around edges to release the doughnut holes.

Melt unsalted butter in a skillet and stir in a splash of vanilla extract. In another bowl, mix granulated sugar with additional cinnamon.

Brush each warm doughnut hole with browned butter and roll in the cinnamon-sugar mixture.