Preheat the oven to 425°F (220°F). Grease a 6-cup muffin tin with nonstick cooking spray and set aside.
In a large bowl, whisk together the flour, baking soda, salt, cinnamon and espresso powder. Set aside.
1 ½ cups whole wheat flour, 2 teaspoons baking soda, ½ teaspoon kosher salt, ½ teaspoon ground cinnamon, 2 tablespoons espresso powder
In a separate small bowl, whisk together the Greek yogurt, honey, and brewed coffee until well incorporated.
¼ cup Greek yogurt, ⅓ cup honey, ¼ cup strongly brewed coffee
Add mixture to the dry ingredients then pour in kombucha, mixing until just combined. Do not over mix.
6 ounces plain kombucha
Scoop the muffin mixture into the prepared muffin tin.
Bake at 425°F (220ºC) for 5 minutes then lower oven temperature to 375°F (190°C) for another 8-10 minutes. Check for doneness by inserting a toothpick into the center of muffin. Toothpick should come out clean or with just a few crumbs stuck to it.
Remove from the oven and allow to cool in the tin.
Meanwhile, strain the coffee beans from the melted butter, pressing on the beans with a spoon or back of a spatula to extract all the butter that you can.
Place butter in the fridge until solidified. Spread on muffins and enjoy!