Stir together flour, baking powder, baking soda, salt, sugar and spices. Cut in butter until mixture resembles coarse crumbs. In a separate bowl, whisk together sour cream, whole milk and maple syrup. Pour the liquid mixture into the dry mixture, and mix until dough holds together. Roll dough out on floured surface to 1/2-inch thick in a rectangle shape. Fold in half and roll again to 1/2-inch thick. Fold in half again and roll to 3/4-inch thick. Cut dough into 10 small rectangles and place on greased sheet pan. Bake at 400° F. for 20 minutes or until golden brown. To make caramel sauce, combine brown sugar, butter, heavy cream and cinnamon together in a medium saucepan and heat over medium-low heat. Cook until thickened, about 7-8 minutes, stirring occasionally. Remove from heat and let cool. Drizzle biscuits with caramel sauce. Top with toasted hazelnuts.