Whisk together dry ingredients in a large bowl
Cut in cubed butter
Fold in cold milk using spatula until dough just forms
On floured surface pat dough to 1" thick rectangle
Fold in half, pat flat again
Cut in half, stack, pat flat again. Do this 2 more times
Roll to 1" thick, cut to biscuits
Put in freezer for 20 minutes
Preheat oven to 400F convection roast
Bake for 20 minutes until golden