Whisk together ingredients and store in an air-tight container or bag.
To Make the Biscuits
Cut the shortening into the biscuit mix.
Add buttermilk gradually as you mix, until the dough forms a rough ball and all sticks together. It should be slightly tacky.
On a floured surface, press dough into a square that is 1 inch thick.
Cut into 6 squares (or smaller if you'd like mini biscuits).
Gently round out the edges of each biscuit and place in buttered baking dish. You can use a cast iron skillet, a cookie sheet, really anything.
For soft edges, place the biscuits 1/4 inch apart. For firm edges, place them 2 inches apart.
Bake at 450º F for about 10-12 minutes or until the bottoms are golden brown and the tops are just starting to brown.
After biscuits are baked, brush tops with melted butter.
You could scale this mix up or down, depending on how much storage space you have for the mix. If you don't have buttermilk, you can substitute regular milk OR mix 2 teaspoons vinegar into regular milk to create buttermilk. The recipe given from the mix makes 6 medium biscuits.The listed nutrition facts are for 1 batch of biscuits.