In a large bowl, stir together the flour, sugar, baking powder, baking soda, and salt until thoroughly combined.
Using a pastry blender, cut the butter into the flour mixture until it resembles coarse cornmeal. Stir in the currants. Make a well in the center of the butter-flour mixture; add the buttermilk all at once. Stir the mixture with a fork until blended.
Turn out onto a lightly floured surface. Divide the dough into two parts. Pat each to form two 6-inch round by 1-inch thick circle. Using a sharp knife, cut each into 8 pie-shaped wedges.
Brush tops of scones with cream; sprinkle with the cinnamon-sugar mixture. Place 1 inch apart on lightly greased baking sheet. Bake in preheated 425* oven for 12 minutes or until golden.