Prepare cherries: Pit the fresh cherries carefully using a cherry pitter or other method, removing most pits to avoid unpleasant bites.
Prepare pie mold: Generously spray a glass pie mold with non-stick spray to prevent sticking.
Arrange cherries: Place the pitted cherries evenly on the bottom of the prepared pie mold, filling it generously.
Make custard batter: In a blender or using an immersion blender, combine 5 eggs, 1 cup half and half, 1 cup heavy cream, 1 1/4 cups sugar, 1 cup sifted flour, a pinch of salt, and 2 teaspoons vanilla extract. Blend until smooth but avoid over-blending to prevent excess bubbles.
Combine and prepare for baking: Pour the custard batter over the cherries in the pie mold. Use a spoon to gently push cherries down if needed; cherries will float during baking.
Water bath setup: Place the pie mold inside a larger baking pan (like a lasagna pan). Pour hot water into the larger pan until it reaches about halfway up the sides of the pie mold to create a water bath.
Bake: Bake in a preheated oven at 325°F to 350°F (160°C to 175°C) for approximately 1 hour to 1 hour 30 minutes, or until the custard is set and no longer jiggles in the center.
Cool and chill: Remove the pie from the water bath carefully. Let cool completely at room temperature until no heat is felt. Then cover loosely with a plate and a glass bowl and refrigerate for at least 4-6 hours, preferably overnight.
Serve: Before serving, dust the top lightly with powdered sugar and decorate with a few whole cherries with stems. Slice and serve as desired.