Preheat oven to 375°F. Generously butter a shallow 2-quart baking dish. Scatter pitted cherries on the bottom of dish in a single layer. Set aside.NOTE: alternatively you may use an 8-inch or 9-inch cast iron skillet
Use an immersion blender to mix together melted butter, eggs, milk, sugar, flour, zest, vanilla, and salt until smooth. Alternatively, use a blender or simply whisk together by hand until smooth.
Gently pour mixture over cherries in prepared baking dish.
Bake for 35-40 minutes, until mixture has puffed up slightly and is lightly browned. Remove from oven and allow to cool slightly, about 5-8 minutes. Sift powdered sugar over warm clafoutis. Serve with additional fresh cherries, if desired. Serve warm or at room temperature.
Cherry clafoutis can be baked one day ahead. Cool to room temperature then store in the fridge covered overnight. Serve at room temperature or gently reheat in the oven.
Store leftovers in an airtight container in the fridge for up to three days.