Preheat your oven to 425°F (220°C) and line a baking sheet with parchment paper.
In a large mixing bowl, whisk together the flour, baking powder, salt, garlic powder, and black pepper.
Add the cold cubed butter into the flour mixture. Using your fingers or a pastry cutter, work the butter into the flour until the mixture resembles coarse crumbs.
Stir in the shredded cheddar cheese and chopped jalapeños until evenly distributed.
Pour in the buttermilk and add the green onions, if using. Mix gently until just combined; do not overmix. The dough should be slightly sticky.
Using a spoon or an ice cream scoop, drop heaping tablespoons of dough onto the prepared baking sheet, leaving about 2 inches between each biscuit.
Bake in the preheated oven for 12-15 minutes, or until the tops are golden and the biscuits are cooked through.
Remove from the oven and let cool for a few minutes before serving.
Notes
Serve warm with a pat of butter on top or a drizzle of honey for an added sweet and spicy flavor. Enjoy!