In a bowl, combine the berries, sugar, vanilla, lemon zest and orange zest. Let these sit for about 15-20 minutes to allow the berries to macerate. In a separate bowl, combine the water and corn starch and then pour into the berry mixture, combine. (Note if you are using strawberries cut them into about the same size as the rest of the berries for an even cooking time).
In a bowl combine the flour, sugar, baking powder and salt. Then using your fingers cut the butter into the flour until it resembles a crumble but work quick enough so the butter does not melt. Then add in the milk and combine, the dough should be lumpy.
Pour the berry mixture into the baking dish. Then scoop mounds of dough over the berries and sprinkle with sugar. Bake in the oven for about 25 minutes covered with aluminum foil and then uncover and bake for an additional 15-20 minutes or until the dough is golden brown in color.
Remove from the oven and allow it to sit at least 15 minutes before serving. This is perfect with a dollop of freshly whipped cream or vanilla ice cream.