Preheat oven to 375º. Butter a shallow 2-quart baking dish. Dust with sugar.
Toss the cherries and rum in a small bowl..
In another bowl, whisk flour, sugar and salt. Add eggs and whisk until batter is smooth.
Whisk in the cream slowly. Stir in the cherries and their juices until just blended.
Pour the batter into the baking dish. Bake until puffed and golden, 33-35 minutes.
Serve hot and puffed or cool to room temperature on a wire rack. The clafouti will deflate as it cools, but will still be delicious.
A clafouti is a simple kind of French fruit pudding. The traditional clafouti is made with unpitted whole cherries (said to add extra cherry flavor).
Alice B. Toklas wrote about clafoutis in her cookbook, from the days when she and Gertrude Stein lived in Paris. You may use any fruit, but cherries are traditional.