Preheat the oven to 400 degrees Fahrenheit and line a cast iron pan or baking sheet with parchment paper.
Cut the butter into small cubes and put back in the fridge to keep as cold as possible.
In a large mixing bowl, combine the flour, salt, baking soda, and sugar. Whisk to combine.
Add the butter to the flour mixture and using your fingers, crumble the butter until pieces are small, around the size of a pea.
Add the lemon zest and raisins to the flour mixture and stir to combine
Pour the buttermilk into the flour mixture and fold the dough with a spatula until dough is shaggy and roughly holds together.
Turn the mixture out onto a floured work surface and knead until all the flour is incorporated. Add flour if dough is too sticky to work with.
Shape dough into a rough ball. Place on the prepared cast iron or baking sheet.
Using a bench scraper or knife, make two large cuts in the dough to almost divide the ball into quarters. Press the pieces back together gently and place in the oven to bake.
Bake for 40-50 minutes or until golden and center of loaf is cooked. If you have an instant-read thermometer, the internal bread temperature will be 195 degrees Fahrenheit when cooked.
Let cool in the pan for ten minutes then transfer to a wire rack to cool completely. Serve warm with butter