1 tablespoon freshly squeezed lemon juice (from the zested lemon)
Instructions
Arrange a rack in the middle of the oven and heat the oven to 375°F. Coat a 2-quart or 11x7-inch baking dish with butter.
Make the crisp topping: Cut 12 tablespoons unsalted butter into tablespoon-sized pieces and place in a medium bowl. Microwave in 20-second bursts until mostly melted, 40 to 50 seconds total (it will melt completely as it sits). Set aside to cool slightly. (Alternatively, melt the butter in a small saucepan over medium heat.)
Place 1 tablespoon finely grated lemon zest, 1 1/2 cups old-fashioned rolled oats, 3/4 cup all-purpose flour or gluten-free all-purpose flour blend, 1/2 cup packed light brown sugar, 1 teaspoon vanilla extract, and 1/2 teaspoon kosher salt in a large bowl and stir to combine. Pour in the melted butter and stir to combine. Refrigerate for at least 5 minutes or until ready to use, the topping will harden when chilled.
Make the filling: Stem and pit 2 pounds sweet cherries if needed. Cut half of the cherries in half. Place all the cherries, 1/2 cup packed light brown sugar, 1/4 cup cornstarch, 1 1/4 teaspoons kosher salt, 1 teaspoon vanilla extract, and 1 tablespoon freshly squeezed lemon juice in a medium bowl. Stir to combine.
Transfer the cherry filling to the baking dish and spread into an even layer. Break the topping into large clumps with your fingers and scatter over the filling in an even layer.
Bake until the crisp topping is golden-brown and the filling is bubbling, 30 to 40 minutes. Let cool for at least 15 minutes before serving.
