Step 1Toss cherries with kirsch and 2 tablespoons granulated sugar in bowl. Let sit 30 minutes.
Step 2Drain liquid from cherries and combine with milk and yogurt. Beat eggs with seeds from vanilla bean in bowl of electric mixer, or with whisk, and add 4 to 6 tablespoons granulated sugar, depending on sweetness of fruit. Slowly beat in flour. Add milk mixture and dash salt. Mix together well. (Ingredients can also be combined in blender and mixed at high speed.)
Step 3Arrange cherries in greased 10-inch or 10 1/2-inch ceramic tart dish or clafoutis dish. Pour in batter.
Step 4Bake at 400 degrees until top is browned and clafoutis is firm, about 45 minutes. Cool slightly on rack. Place 2 to 3 teaspoons powdered sugar in strainer and tap it above clafoutis to dust. Serve warm.