Preheat the oven to 375°. Generously grease a 9-inch cast iron skillet with vegetable shortening.

Combine the flour, sugar, baking soda, and salt in a large bowl; whisk gently to blend. Stir in the raisins to coat with the flour mixture. Make a well in the center and add the buttermilk and egg; stir until a stiff dough forms. (Use a wooden spoon if you must, but the most efficient way to mix this soft, sticky dough is with floured hands. Alternatively, the dough can be mixed in a heavy-duty stand mixer fitted with the dough hook.)

Remove the dough from the bowl and mound it into the prepared skillet, roughly forming a round loaf. (Don’t be concerned that it won’t hold its shape; it will be corrected during baking.) Lightly moisten your hands with water to smooth the top. Using a serrated knife dipped in fl our, score the top with a large X, about 1?2-inch deep. (This will ensure even baking, and it will also scare away the devil, according to Peggy’s mother.) Bake until the loaf is golden brown with a firm crust and the bottom sounds hollow when tapped with a knife, about 1 hour.

Remove the bread from the skillet and let cool on a wire rack at least 30 minutes before cutting into 1?2-inch-thick slices. Serve warm, at room temperature, or toasted, with or without butter.