Combine flour, sugar, baking soda, baking powder, and salt. Cut butter into flour mixture with pastry cutter. Add buttermilk until dough is soft. Stir in currants.
Turn dough out onto a lightly floured surface. Knead for 5 minutes, or until smooth. Form dough into a 7 inch round. Place on a lightly oiled cake pan or cookie sheet. Cut 1/2 inch deep cross side to side. Score with cross 1/2 inch deep on the top.
Bake in a preheated 375 degrees F (190 degrees C) oven for 40 minutes.