Make the biscuits: Beat the cream cheese, butter, granulated sugar, grated ginger and salt in a large bowl with a mixer on medium-high speed until light and fluffy; reduce the speed to low and beat in the flour and candied ginger until just incorporated. Turn the dough out onto a sheet of plastic wrap; press into a 1-inch-thick disk, tightly wrap and refrigerate until firm, about 1 hour or overnight. On a floured surface, roll out the dough into a 10-inch circle, about 1/2 inch thick. Use a 2 1/2-inch biscuit cutter to cut out rounds; arrange about 1 inch apart on a baking sheet. Reroll the scraps and cut out more biscuits (you should have 12). Brush the tops lightly with the heavy cream and sprinkle with the demerara sugar. Refrigerate until firm, about 20 minutes. Position racks in the upper and lower thirds of the oven and preheat to 350 degrees F. Bake the biscuits until slightly puffed and golden brown, 25 to 30 minutes. Let cool 5 minutes on the baking sheet, then remove to a rack to cool completely.
Meanwhile, make the toppings: Puree half of the strawberries in a blender with 1/4 cup granulated sugar and the grated ginger until smooth; transfer to a bowl. Dice the remaining strawberries; add to the pureed berries and toss. Beat the sour cream, heavy cream and the remaining 2 tablespoons granulated sugar in a separate bowl with a mixer on medium-high speed until soft peaks form. Serve each person 2 biscuits with the whipped cream and strawberry mixture. Photograph by Anna Williams