Preheat the oven to 425 degrees Fahrenheit. Line a baking sheet with parchment paper and set aside.
In a bowl, whisk together 2 ¼ cup all-purpose flour, 2 teaspoons baking powder, ¼ teaspoon baking soda, and 1 teaspoon salt. Cut the 8 tablespoons cubed cold butter, into the flour mixture with a pastry cutter or a fork until it resembles coarse crumbs.
Add the ¾ cup cold buttermilk and use a spatula to combine till a rough dough forms.
Turn the dough out on a floured work surface and gently bring the dough together with your hands, being careful not to overwork it.
Roll the dough out into 1/2 inch thickness and cut 10-12 biscuits. While cutting the biscuits, don't rotate the cookie cutter.
Transfer the biscuits to the lined baking sheet. Brush with 2 tablespoon buttermilk, and bake for 15 minutes till the top is golden brown. Serve warm.