Preheat the oven to 350°F. Lightly butter a baking pan large enough to hold the cherries loosely in a single layer. Prepare the cherries and arrange them in the pan. Sprinkle with the lemon juice, zest, cinnamon, and sugar. Bake until the fruit is tender, about 15 minutes, stirring once or twice.

Raise the oven temperature to 375°F. Butter another gratin dish large enough to hold the cherries in a single layer, or use four individual gratin dishes. Drain the cooked cherries, reserving their juice in a small saucepan. Arrange the cherries in the bottom of the baking dish. Beat together the egg yolks and sugar until well blended. Beat in the flour, vanilla, almond extract, and cream.

Beat the egg whites with a pinch of salt until they form soft peaks. Stir a little of the whites into the batter, and then carefully fold in the rest. Pour the batter over the fruit in the baking dish, letting a little fruit show through the top.

Bake in the upper third of the oven for about 20 minutes, until the batter has puffed and browned. While the clafoutis is baking, reduce the fruit juices to a thin syrup. When the clafoutis is done, dust it with powdered sugar and serve warm with a drizzle of the syrup.