Preheat oven to 425℉
In a large mixing bowl, combine flour, garlic powder, paprika, sea salt and baking powder until fully combined
Using a knife, fork or pastry blender, cut the cold butter into the flour mixture until it resembles coarse crumbs
Add the sourdough discard and milk, and lightly mix with a spoon
Add the shredded cheddar cheese, and mix until fully combined
Transfer the dough on a floured surface and lightly knead to ensure dough is evenly mixed
Gently pat dough until it is 1" thick
Using a 2 ⅜" biscuit cutter, cut out as many biscuits as possible. I usually get 3.
Fold and reshape the leftover dough until it is 1" thick and cut out more biscuits
Repeat until all dough is used
Transfer the biscuits to a baking sheet lined with a silicone baking mat, parchment paper or greased foil
Bake for 22-25 minutes, or until golden brown and firm on top
Remove from oven and immediately butter the tops before serving