In a large bowl, mix together the first 5 ingredients and set it aside.

Grate the cold butter using a box grater. Cut the grated butter into the flour mixture using a pastry cutter until the mixture is crumbly. Create a small well, add in the beaten egg and cold buttermilk and mix with a wooden spoon until combined and sticky. Cover and refrigerate for 30 minutes.

While the dough is chilling pre-heat the oven to 400 degree F.

On a flour-dusted counter turn out the chilled dough, using floured hands, pat it out quickly and gently into a rectangle about 6" x 10". Fold about 3 inches of dough over itself from the right end, fold the opposite end over the folded right end, creating three layers, turn it 90 degrees and gently pat that down again into a rectangle and repeat folding about five times. Pat it out one last time to about 1/2" thick.

Using a 2.5" biscuit cutter dipped in flour, cut out biscuits. Don't twist the cutter, press and pull straight up. Press together any scraps to create biscuits. Place biscuit close together on a stoneware cookie sheet.

Bake for 17-24 minutes, until golden brown and cooked through.

Store in an airtight container for up to three days.