Trim the berries, if necessary. Place the mixed berries in a large bowl. Pour 1/2 cup sugar over the top and add the lemon juice and vanilla. Mix well to coat. Divide the mixed berries evenly between the ramekins.
In a large bowl, mix the remaining 1/2 cup sugar, flour, cornmeal, baking powder, and salt. Pour in the milk and melted butter. Whisk until smooth.
Spoon the cornmeal batter evenly over the fruit in the ramekin cups. Sprinkle the tops with sliced almonds.
Bake the cobbler cups for 40-45 minutes, until the edges are bubbling and the tops are golden. Cool 10 minutes before serving. Serve as-is or with a scoop of vanilla ice cream.
This recipe can be made up to 4 days ahead, and rewarmed. Keep in the refrigerator.