• 1 1/2 c. heavy whipping cream
To prepare dough: Line a baking sheet with parchment paper. In a medium bowl, whisk together flour, 3 tablespoons sugar, baking powder, 1/4 teaspoon salt, crystalized ginger and lemon zest. Add diced butter and, using your hands (or 2 knives, or a pastry cutter), break up mixture until butter is the size of peas. Add buttermilk and stir just until dough comes together. Form dough into 8 or 9 equal-size balls (8 for a round baking dish, 9 for a square one) then gently shape into flattened biscuits. Transfer biscuits to prepared baking sheet and refrigerate for at least 30 minutes and up to 4 hours.
To prepare filling: Preheat oven to 350 degrees. In a medium bowl, combine strawberries, rhubarb, lemon juice, 2/3 cup sugar, cornstarch and pinch of salt. Allow to macerate for 15 minutes. Pour filling into a 2-quart ceramic dish and top with cobbler biscuits. Brush biscuits with heavy cream and dust with sugar. Bake until biscuits are golden and filling is bubbling, about 60 minutes. Remove from oven, transfer dish to a wire rack and cool 30 to 45 minutes.
To prepare topping: In a bowl of an electric mixer, combine heavy cream and 3 tablespoons sugar and beat until soft peaks form. Serve cobbler topped with whipped cream.