In a large bowl, combine both flours, baking powder, granulated sugar and salt. Rub the butter into the flour mixture using your fingers or a pastry blender until the butter resembles pea-sized clumps distributed through the flour. Add the chocolate chips. Stir in the milk and heavy cream forming a soft dough.

Preheat the oven to 400 degrees F.

On a lightly floured work surface, pat the dough into a 7-inch diameter circle. Cover with plastic wrap, transfer to the refrigerator and chill for 30 minutes. Cut the dough into 6 equal wedges and place on a parchment paper-lined sheet pan. Brush the scones with heavy cream and sprinkle with turbinado sugar.

Bake for 25 minutes until golden brown. Serve warm or at room temperature. Store in an airtight container.