Zucchini Mock Apple Cobbler

From the garden

• 8 cups overgrown zucchini or yellow summer squash, peeled, seeded, sliced 1/4 inch thick · about 3 pounds, which is one marrow you lost track of

From the pantry

• ½ cup lemon juice, freshly squeezed (about 3 lemons) · the acid is what makes it read as apple; do not cut it back
• 1 cup granulated sugar · for the filling
• 1 tsp ground cinnamon · for the filling
• 2 tbsp cornstarch, whisked with 2 tablespoons cold water
• 3 cups all-purpose flour · for the crumb
• 1 tsp ground cinnamon · for the crumb
• 1 cup brown sugar, packed · for the crumb
• 12 tbsp butter, cold, cut into cubes · plus a little more for the dish
• ½ tsp salt
• heavy cream (optional) · to pour over, or vanilla ice cream

1. Heat the oven to 375°F and butter a 9x13-inch dish. Peel the squash, halve it lengthwise, scrape out the seedy core with a spoon, and slice the firm flesh 1/4 inch thick to make 8 cups.
2. Simmer the slices with the lemon juice in a wide pan over medium heat, stirring now and then, for 8–10 minutes, until they turn translucent at the edges and bend without snapping.
3. Stir in the granulated sugar and cinnamon, then the cornstarch slurry, and cook 1 minute more until the juices thicken and go glossy. Off the heat it should already taste startlingly like apple pie filling.
4. Rub the flour, cinnamon, brown sugar, and salt together with the cold butter, using fingertips or a pastry cutter, until the mixture clumps when squeezed and no dry flour is left.
5. Press half the crumb firmly into the dish and bake 10 minutes to set the base. Spread the warm filling over it and scatter the rest of the crumb on top in loose clusters.
6. Bake 30–35 minutes, until the top is deep golden and the filling bubbles thickly at the edges. Rest 20 minutes so it sets from loose to sliceable, then serve warm with cream.