In a medium bowl, stir together strawberries, raspberries, sugar, and lemon juice. Let stand until a fruit syrup forms, about 20 minutes.
Preheat oven to 375°F (190°C).
In a large bowl, stir together flour, milk, pistachio meal, baking powder, cardamom, rosewater, and salt. Stir in melted butter until well combined. Pour into an ungreased 8-inch square baking pan, smoothing top. Spoon berry mixture over batter. (Make sure to pour the fruit mixture over the batter quickly. If the batter cools too much, the fruit won’t sink as well.)
Bake until golden brown, 35 to 45 minutes, loosely covering with foil halfway through baking to prevent excess browning. Cover and refrigerate for up to 3 days.
Notes
To make pistachio nut meal, grind roasted and salted pistachios in a food processor.
Recipe by Bake from Scratch at https://www.bakefromscratch.com/strawberry-raspberry-cobbler/