Preheat oven to 400 degrees, spray a baking sheet with non-stick cooking spray or lightly oil; set aside.
In a large mixing bowl combine the flours, Splenda, sugar, baking powder, salt and cream of tartar.
With a pastry blender, cut in the mascarpone cheese and butter; set aside.
In a small bowl, combine egg yolk, yogurt, milk and extract; add the creamed mixture to the flour mixture; mixing until a soft dough forms.
Sprinkle the 1 tablespoon of flour over the cherries and pecans, toss to coat.
Turn dough out onto floured surface; knead gently, kneading in additional flour if needed along with cherries and pecans; place the kneaded dough onto prepared pan and pat into a 6 inches circle, cut into eight wedges; brush with egg white; sprinkle with sugar.
Bake in preheated oven for 20 to 25 minutes. Serve warm with additional mascarpone cheese if desired.