Preheat oven to 400 degrees F. Lightly butter a large baking sheet. In a mixing bowl, combine the flour, sugar, baking soda, baking powder, salt, ginger, and zest. Cut in the butter with a pastry blender until the mixture resembles fine crumbs. In a separate bowl, combine the cream, lemon juice, and lemon extract and stir this mixture into the dry ingredients until a soft dough forms. Scrape the dough onto a lightly floured surface. Knead twice with floured hands. Place the dough in the center of the greased baking sheet and flatten into an 8-inch circle. Using a sharp knife, cut the dough into 8 wedges. Separate the pieces slightly. Lightly brush the surface of the dough with cream. Bake for 20 minutes, until golden brown. Cut the wedges apart. Transfer to a cloth-lined basket and serve at once.