Chop bacon into small pieces and cook over medium heat until crispy. Remove and place on a paper towel-lined plate to drain off excess bacon fat.
Preheat oven to 450 degrees with rack positioned in the middle.
Mix together flour, baking powder, baking soda, salt in a large bowl. Add bacon, cheese and chives (if desired), stirring well.
Grate frozen butter into mixture using a box grater, mixing every so often to keep from clumping.
Slowly add buttermilk to mixture, stirring with wooden spoon or spatula. Combine until dough forms, but be careful not to overmix.
Dump out dough onto floured surface and knead a few times to remove any air bubbles. Once dough has formed a roughly round ball, roll with floured rolling pin to a 1 1/2-2-inch thickness.
Using a round cookie cutter or open mouth of a drinking glass, cut out about a dozen biscuit rounds. You may have to recombine the leftovers and re-roll flat again to use all the dough when cutting out the rounds.
Place biscuit rounds on a plate in the freezer for about 12-15 minutes. This will help them cook uniformly.
Remove biscuits from freezer, place on lined baking sheet, and bake for 15 minutes or until top is golden brown. Remove from oven and let cool slightly before serving.