Heat oven to 425 °F convection bake and position rack to the middle position.
Take 1/2 lb bacon and cut it into 1/2 inch chunks. Cook on the stovetop until done. Drain on paper towel and allow to cool.
If making your own buttermilk, do that now. See notes.
In food processor fitted with the blade attachment, combine 2 cups of flour, 3 Tbsp cornstarch, 1/2 tsp baking soda, 1 Tbsp baking powder, 1 Tbsp sugar, 1 tsp salt, 1/2 tsp garlic powder, and 2 tsp oregano. Pulse a few times to mix completely.
Add the 10 Tbsp frozen butter and pulse until coarse. The mixture should look like coarse crumbs. Don't overmix. If mixing in a bowl rather than a food processor, grate frozen butter into the flour mixture and stir to combine.
Transfer the mixture to a mixing bowl and stir in 1 cup shredded cheddar cheese, and 1/2 lb cooked and crumbled bacon. Add buttermilk and stir just until the dough comes together. It should look like a shaggy ball. Again, don't overmix. If it looks too dry, you can add a bit more buttermilk, milk, or heavy cream.
Lightly flour a surface, and turn the dough onto the counter. Pat the dough together into a ball and then shape it into a rectangle about 1 inch thick.
Using a sharp knife or pastry cutter, cut the rectangle into thirds. Stack the dough rectangles one on top of the other and then press them into a 1" thick rectangle (see video tutorial for help).
Lightly flour the surface again. Repeat the process above, cutting it into thirds, stacking, and then pressing. This time, press it into a square about 3/4" thick. I square off my edges using a pastry cutter.
Using a sharp knife or pastry cutter, cut the square into 9 each parts, 3x3.
Transfer each biscuit to a baking sheet prepared with parchment paper or a silicone baking mat, and bake for 12-14 minutes. Biscuits will be golden brown on the top.
These biscuits are best enjoyed immediately, but I reheat mine by tearing them in half and heating them at 360°F in the air fryer for a few minutes.