Preheat your oven to 425°F and line a baking sheet with parchment paper. Cube cold butter, and set aside in a small bowl in the fridge.

In a large bowl, lightly toss your dry ingredients together: flour, baking powder, sugar, salt, cheddar, scallions and serranos.

Add in your butter, and with your fingers, work the butter into the flour mixture. It should resemble rough crumbs. Press down the butter cubes between your thumb and index finger to help get everything into the flour. You want small, almost pea-sized bits of butter tossed throughout the dough.

Slowly pour in the buttermilk, in two batches, gently stirring with a spoon or spatula until the dough somewhat stays together. The dough will be shaggy and textured. Don’t worry, this is what we want! Be careful not to overmix.

Transfer the dough onto a lightly floured surface, and using a bench scraper, gently pat the dough into a 1-inch thick rectangle. Cut the dough into fours, placing each piece of dough on top of the other, so there are 4 square doughs stacked on each other. Now, pat down this stacked dough back into a 1-inch thick rectangle. Repeat this step 3 to 4 times to establish all your biscuits layers.

Cut your biscuits evenly into 9 square biscuits, 1-inch thick.

Transfer your biscuits to your prepared baking sheet, and transfer to the freezer for 15 minutes.

Then transfer to the preheated oven on the middle-to-highest rack, and bake for 20 to 25 minutes, depending on the heat of your oven. Halfway through cooking, flip the sheet pan the other way to allow even browning on all of your biscuits.

Once your biscuits form a golden brown crust and are cooked through, remove them from the oven and butter the tops of your biscuits with a brush using your melted butter. Serve warm.