Optional: Combine liquid flavoring with the buttermilk.
Combine flour, baking powder, baking soda, sugar, & salt in a large bowl.
Combine the shredded butter with the dry ingredients. Incorporate until the largest lumps are about the size of peas.
Pour the buttermilk into the dry ingredients and then incorporate the components gently with a spatula. Avoid over mixing.It’s okay if the dough appears to be a little bit dry and the butter shreds are noticeable.
On a lightly floured surface, pat the shaggy dough together and complete a fold. Afterwards, roll it out, repeating the fold-and-roll process four or five times. The dough should be around 1" tall when finished.
Cut biscuits using a biscuit cutter.
Place on an ungreased baking sheet and brush with the egg wash. Bake 10-12 minutes or until golden brown.
Optional: After cooling, gloss with additional liquid flavoriing.