1 ½ cups (10 ounces) all-purpose flour, plus 1/4 cup more for dusting
½ cup rye flour
2 tsps baking powder
¾ tsp baking soda
½ tsp kosher salt
1 stick unsalted very chilled butter, diced
1 cup chilled buttermilk
Heat oven to 400 degrees.
Whisk together flour, rye, baking powder, baking soda, and salt. Cut in the butter until you have pea size crumbs and flour is coated with butter. Stir in the buttermilk.
Dust work surface with ¼ cup flour.
Pat dough into a rectangle. Fold the dough over on itself a few times and pat out to a 3/4 inch thickness. Punch out 8 biscuits with (2 ¾ inch) ring mold or biscuit cutter and place into a 10 inch cast iron skillet. Bake for 12-14 minutes, until golden brown.