Lightly spoon flours into dry measuring cups; level with a knife. Combine flours, sugar, baking powder, salt, and cardamom in a large bowl; cut in butter with a pastry blender or 2 knives until mixture resembles coarse meal.
Combine buttermilk, rind, vanilla, and egg in a medium bowl; stir in dried pears. Add buttermilk mixture to flour mixture, stirring just until moist (dough will be sticky).
Turn the dough out onto a lightly floured surface. Dust top of the dough with 2 teaspoons all-purpose flour, and pat into an 8-inch circle. Cut dough into 8 wedges; arrange wedges 1/2 inch apart on a baking sheet coated with cooking spray. Brush egg white over wedges. Bake at 350° for 25 minutes or until golden. Serve warm.