Step 1: Prep

Preheat the oven to 375 degrees F. Butter a 2-quart shallow baking dish or eight 6-ounce ramekins.

Step 2: Pick a Nut

Chop 3/4 cup of any of these nuts, shelled: walnuts almonds pistachios pecans hazelnuts

Step 3: Choose a Grain

Put 1/2 cup rolled oats or cornmeal in a bowl. Add 3/4 cup flour, 1/2 cup light brown sugar and a pinch of salt and whisk.

Step 4: Mix the Crumble

Add the nuts to the bowl. Work in 7 tablespoons softened butter with your fingers until evenly moistened; set aside.

Step 5: Make a Filling

Apple-Raspberry: Peel 3 pounds baking apples (such as Macoun or Cortland); cut into 3/4-inch chunks. Toss with 2 cups raspberries, 3 tablespoons granulated sugar, 2 tablespoons flour, 1 teaspoon vanilla and a pinch each of nutmeg, cinnamon and salt.

Plum-Nectarine-Blackberry: Halve and pit 4 nectarines and 2 plums (no need to peel); slice 1/2 inch thick. Toss with 2 cups blackberries, 1/2 cup granulated sugar and 1 tablespoon flour.

Pear-Pineapple: Peel 3 pounds baking pears (such as Bartlett); cut into 3/4-inch chunks. Combine with 3 cups pineapple chunks, 2/3 cup granulated sugar, 1/2 teaspoon ground ginger and 1/4 teaspoon each salt and cinnamon in a skillet; cover and cook over medium heat, stirring, 12 minutes. Stir in 2 tablespoons flour; cook 1 more minute.

Blueberry: Toss 4 cups blueberries, 1/3 cup granulated sugar, 1 tablespoon flour and 1 teaspoon lemon juice in a bowl. (If you are using ramekins, double the blueberry filling.)

Quince-Grape: Peel 3 pounds quinces; cut into 1-inch chunks. Toss with 1/2 cup granulated sugar, 1/3 cup water and a pinch of salt in a skillet; cover and cook over medium heat, stirring occasionally until tender, 15 to 20 minutes. Stir in 1 pound seedless red grapes and 1 tablespoon flour.

Step 6: Bake

Transfer the filling to the prepared dish or ramekins and dot with 2 tablespoons cut-up cold butter. Squeeze handfuls of the crumble mixture and scatter on top of the fruit. Bake until golden and bubbly, 40 to 45 minutes. Let sit 10 minutes before serving. Top with whipped cream or ice cream, if desired.