Preheat oven to 375°F.
Whisk together the flour, sugar, salt and baking soda.
Using a box grater, grate the COLD butter over the dry ingredients. Using your fingers, rub the butter throughout the flour mixture.
Toss the raisins into the flour mixture to coat; distribute equally.
Whisk egg into buttermilk. Make a well in the center of the flour mixture and pour it in. Stir with a wooden spoon just until ingredients are all incorporated.
Turn dough onto a floured board. With floured hands, shape into a round mound of dough.
Place it in a buttered cast iron pan. Cut a cross pattern on the top and place into the preheated oven for 50 minutes.
If you tap on the top and it sounds hollow, it is done! Remove from pan to a cooling rack.
Allow it to rest a little before slicing.
Wrap any leftover bread with plastic wrap, then foil. Store at room temperature. Slice some later, toast it and spread on some butter or jam or both! Serve with some tea!