For the crumble:
6 tablespoons unsalted butter
1 cup flour
2/3 cup sugar
1 teaspoon baking powder
1/4 teaspoon salt
1 large egg, beaten well
Position a rack in the center of the oven, and preheat the oven to 375°F.
Spread the frozen cherries in an ungreased 9x9-inch baking dish, deep pie pan, or similar-sized dish. Toss the cherries with the sugar, flour, ginger, cinnamon, and salt.
Cut the butter into several pieces and melt over low heat in a small saucepan. Raise the heat slightly after it has melted, and cook, swirling frequently, until the butter has turned nutty brown. Remove from the heat.
In a medium bowl, combine the flour, sugar, baking powder, and salt. Add the beaten egg and use your hands to combine the dry ingredients and egg. As you work the egg into the flour, it will form small moist crumbs. Sprinkle these over the cherries, then drizzle the browned butter over the topping.
Bake for 30 to 35 minutes, or until the top is browned and the cherries are bubbling. Cool for at least 30 minutes before serving. Serve warm or at room temperature with vanilla ice cream or unsweetened whipped cream.