Preheat the oven to 425°F. In a small bowl, whisk together the flour, sugar, onion powder (if using), salt, and baking powder.
In a food processor, pulse the flour mixture and cold butter together. Slowly pour in the buttermilk and continue to process until a sticky dough forms. Transfer to a bowl and gently fold in the shredded cheddar cheese.
Using a greased 1/3 measuring cup, scoop the dough and drop it onto an ungreased baking sheet.
Bake for 15-20 minutes or until the biscuits are golden brown on top and cooked through.
Serve warm with butter and your favorite hot soup. Enjoy!