Preheat oven to 350° F
Lightly grease cast iron pan with unsalted butter
Sift together flour, baking powder, baking soda, salt and sugar in a medium bowl
Grate your cold butter into the dry ingredients
Sprinkle in caraway seeds and currants (or raisins). Mix together to combine.
In a separate bowl, whisk together eggs and buttermilk.
Add buttermilk mixture to the dry ingredients and mix with a spoon (or your hand) until the dry ingredients are moistened.
Place the dough on your workbench and fold 7-8 and shape it into a ball. Do not over-work the bread or it will be tough.
Dust the surface generously with flour and use a sharp knife to cut an x on top to allow the dough to spread and rise evenly.
Place the dough into the cast iron pan.
Bake for 1 hour and the top is golden brown or the internal temperature reads 190º-200ºF