In a large bowl, combine flour, 1/4 cup sugar, baking powder, baking soda, and salt.
Using a pastry cutter or your fingertips, cut in butter until mixture resembles course crumbs. Stir in cranberries, chocolate chips, and 1 teaspoon orange zest. Add yogurt and 1/3 cup buttermilk and stir just until moistened.
Shape dough into a loose disc and turn onto baking sheet. Finish shaping dough into a roughly 8" round with your hands. Cut into 8 wedges; do not separate. Brush with 1-2 teaspoons buttermilk. Sprinkle with sugar and remaining 1/2 teaspoon orange zest.
Bake 15-20 minutes or until edges begin to turn golden brown. Cool 5 minutes. Cut into wedges; serve warm with sweetened whipped cream and jam or cool completely.
Store in an airtight container for up to 3 days. Reheat in oven.