Fragrant with the sunshine of lemon zest, the crackly almond roof of this summer-in-a-dish dessert gives way to jammy berries begging to be swirled with ice cream. To make this dead simple treat even easier, the crisp topping is simply stirred with melted butter, which binds together the dry ingredients while giving the mixture a sturdiness that holds up against the juicy fruit. Sliced almonds require no chopping and add a delicate crunch, but chopped pecans would be delicious here too, as would pinches of spices, such as cinnamon, nutmeg, cardamom or even black pepper. The topping can be refrigerated for up to 3 days ahead of time. Pro potluck tip: Ask the host if you can use the oven, and if you can, bring the berry mixture in the baking dish and the chilled topping in a separate container. When you arrive, scatter the crumbs over the filling and bake to perfume the house and enjoy a warm dessert.
Ingredients for the topping:
• 1 lemon
• 1/2 cup/100 grams sugar
• 1 cup/136 grams all-purpose flour
• 1/2 cup/52 grams sliced almonds, toasted if you’d like
• 1/2 teaspoon fine salt
• 1/2 cup/114 grams unsalted butter, melted and cooled
Ingredients for the filling:
• 1/2 cup/100 grams sugar
• 1 1/2 packed tablespoons cornstarch
• 2 to 2 1/4 pounds blueberries
• Ice cream, for serving
Heat the oven to 375 degrees. Prepare the topping: Zest the lemon directly over the sugar in a medium bowl and mix with a fork. (Save the zested lemon for the filling.) Mix in the flour, almonds and salt.
The cooled melted butter has likely separated, so stir it until evenly pale yellow, then drizzle over the dry ingredients. Stir lightly and quickly until the mixture forms pea-sized crumbles with gravelly bits; don’t overmix. Refrigerate until ready to use. The topping can be covered and refrigerated for up to 3 days.
Make the filling: Whisk the sugar and cornstarch in a large bowl to break up starchy clumps. Add the blueberries and squeeze in 1 tablespoon lemon juice from the reserved zested lemon. Toss until evenly coated, then scrape into a 1 1/2to 2-quart casserole (such as a 9-inch square dish or deep-dish pie plate).
Spread the berry filling in an even layer, then cover with the topping, leaving no gaps. Place the dish on a rimmed baking sheet to catch any drips.
Bake until the topping is golden brown and the filling is bubbling like lava, 40 to 45 minutes. You don’t want to burn your mouth eating the crisp hot, so let it cool for at least 15 minutes and preferably an hour or so because the filling firms up as it cools. It can be served warm or at room temperature, ideally with ice cream.
Total time: 1 hour 20 minutes, serves 6-8.