In a large bowl, mix together the flour, baking powder, and salt. Grate the butter in the large hole-setting of a grater above the bowl, stopping to stir and coat the butter bits in the flour mixture every 10 seconds. Pinch the mixture together with your fingertips until crumbly, like damp sand. Set aside 2 tablespoons of the grated Cabbot cheddar cheese, and add the remaining Cabot cheddar, garlic, and rosemary to the flour mixture and stir gently to evenly distribute throughout.

Add 1 cup plus 2 tablespoons of the buttermilk, breaking the additions into 4 increments, stirring gently for 10 seconds after each addition with a fork. If needed, add 2 additional tablespoons of buttermilk to help dough come together (the amount of buttermilk depends on how humid or dry your cooking environment is). The dough should *just* hold together when you squeeze it in your hand.

Gently roll the dough into a rough rectangle that's 1-inch thick, then fold the rectangle up like a letter (see process photos below). Pat down on the folded dough, rotate it so that it's lengthwise facing away from you (this will make it easier to roll out) and roll it until it's 3/4 inch thick. Use a 2 1/2-inch round cookie cutter to cut the biscuits. Pat any remaining dough into rough rectangle shape, then roll out until it's 3/4 inch thick and cut it with the biscuit cutter again to get as many biscuits out of the remaining dough as you can. You should end up with 12 to 14 biscuits.

Flip the biscuits over (the bottom is usually flatter and more attractive) and place them on a baking sheet lined with parchment paper, spaced about 1/2-inch apart. Cover them and place them in the freezer for 30 minutes.

Preheat the oven to 425 degrees Fahrenheit. Lightly brush the top of each biscuit with buttermilk and sprinkle with a small pinch of the remaining grated Cabot cheddar cheese. Place in the oven and bake until the tops of the biscuits are golden brown, about 17 to 20 minutes.