01 -
Grease a cast iron skillet or oven-safe baking dish with butter. Preheat the oven to 175°C.
02 -
In a blender, mix eggs, whole milk, heavy cream, all-purpose flour, granulated sugar, vanilla extract, and salt until the batter is smooth and free of lumps. Alternatively, whisk thoroughly by hand.
03 -
Pour the batter into the prepared baking dish. Distribute the fresh blackberries evenly on top; they will settle slightly during baking.
04 -
Bake for 35 to 40 minutes until the custard is puffed, golden at the edges, and gently set in the center with a slight jiggle.
05 -
Allow to cool for 10 to 15 minutes. Optionally dust the surface with powdered sugar before serving warm or chilled.