Stir brown sugar and cinnamon together in a large bowl; add pear slices and toss until coated with mixture. Spray a large nonstick skillet with cooking spray and place over high heat. When very hot, add pears and cook, stirring frequently, for 2 to 4 minutes or until brown sugar has turned thick and syrupy. Transfer back to bowl and stir in cornstarch and cherries. Roll dough into 6 equal balls. Roll each ball into a 6 inch circle on a lightly floured board. Place equal amounts of fruit in the center of each and bring the edges up to form a shell. Pinch lightly to secure dough around fruit. Brush with egg and sprinkle with coarse sugar, if desired. Bake on a parchment-lined baking sheet for 20 minutes or until crust is golden brown. Best served warm.