Preheat oven to 450 degrees F. Line a baking sheet with parchment paper.
Cook bacon on medium high heat until brown and crispy, about 6-8 minutes. Transfer bacon to a paper towel-lined plate to remove any excess fat.
In a large bowl, combine sifted flour, baking powder, salt and baking soda. Add bacon, grated cheese and chopped green onions.
Grate butter using the large holes of a box grater. Stir into the flour mixture gently with a rubber spatula. Add buttermilk and stir using a rubber spatula until a soft dough forms. DON"T OVERWORK THE DOUGH.
Working on a lightly floured surface, knead the dough 3-4 times until it comes together. Roll the dough into a 1 1/4-inch thick rectangle using a rolling pin. Cut out 12-15 biscuits, about 2 1/2 inches each biscuit. Place biscuits onto the prepared baking sheet; place in the freezer for 15 minutes.* SEE NOTES if making ahead.
Remove biscuits from freezer. Place into oven and bake for 17-20 minutes, or until golden brown. If you make these smaller, they bake in about 15-17 minutes and the larger bake longer. To check if fully baked, remove on, open in the middle and if it still needs a few more minutes, continue baking. Each oven is different so results and timing might be slightly different.
Serve warm with butter, jam or make a egg sandwich.
*IF MAKING AHEAD - freeze biscuits separately, then transfer into a freezer bag or container. Keep in freezer until ready to bake and serve warm.