For the topping:

For the filling:

For the lime/ginger whipped cream:

For the topping:

In a large bowl, combine the flour, baking soda, cream of tartar, 4 tablespoons of the sugar, and salt. Cut in the butter and shortening until the mixture resembles coarse crumbs. Add the milk and cream and stir just to combine. Do not overwork the dough. Pat the dough into a flattened disk, wrap with plastic wrap, and refrigerate until ready to bake the cobbler, at least 1 hour and up to overnight.

For the filling:

Preheat the oven to 350 degrees F. Butter an 8 by 11-inch casserole dish with 1/2 tablespoon of the butter.

In a medium saucepan, combine the peaches with the sugar, water, cornstarch, and lemon juice and let sit for 15 minutes. Bring to a boil over medium-high heat and cook, stirring frequently, until sauce thickens and peaches have softened, about 7 minutes. Remove from the heat and stir in the remaining 2 tablespoons butter, blueberries, and vanilla extract. Transfer to the prepared baking dish and set aside while you roll out the dough.

On a lightly floured work surface, roll the dough out to a thickness of about 1/2-inch. Using a 2 1/2-inch biscuit cutter, cut as many circles of dough as possible and arrange them evenly over the top of the peach-blueberry mixture. Sprinkle the tops of the biscuits with the remaining 2 tablespoons of sugar and bake for 25 to 30 minutes, or until biscuits are golden brown and filling is bubbly and thick around the edges.

Cool for 10 minutes before serving. Serve warm with ice cream and lime/ginger whipped cream.

For the lime/ginger whipped cream:

Add the heavy cream and the sugar in the bowl of a stand mixer fixed with a whip attachment. Whip the cream to soft peaks and then add the candied ginger and the lime zest and continue to whip until whipped cream consistency.