Preheat oven to 425°F Line a large baking sheet with parchment paper or butter lightly.
In a measuring cup or bowl, whisk together milk, vinegar and chili powder; set aside.
In a large bowl, combine flour, cornmeal, sugar, baking powder, baking soda and salt. Using a pastry blender or 2 knives, cut in butter until mixture is crumbly. Stir in 1 cup of the cheese and corn (if using). Pour in Milk mixture; stir with fork just until a soft, sticky dough forms. Drop dough by large spoonfuls onto prepared baking sheet; sprinkle tops with remaining cheese. Bake for about 15 minutes or until golden brown and firm to the touch. Transfer to rack to cool slightly. Serve warm.
COOKING TIP: Extra biscuits can be cooled, wrapped in plastic wrap and frozen in an airtight container for up to 1 month. Warm in a 350F oven for about 15 minutes before serving.