Preheat the oven to 400 degrees F and lightly grease muffin tins with softened butter.
In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda and salt. In a separate bowl, whisk together the buttermilk, eggs and vanilla extract (note: this is where you'd add the kirsch if using).
Pour the wet ingredients into the dry followed by the butter and cherries, using a spatula to stir the ingredients together until just combined. The less you mix, the more delicate the muffins will be.
Evenly scoop the muffin batter into the prepared pans, filling 3/4 - 4/5 of the way up.
Bake for 20-22 minutes, or until cooked through. Allow to cool for 5 minutes and then remove carefully from the pan (I find gently twisting works best).
I used Lodge cast iron muffin tins to prepare this recipe, which are slightly smaller than standard muffin pans, hence the tentative yield. You can use a regular 12 cup muffin tin and up the cherry quantity by around 1/4 - 1/3 cup to fill in the space!