To prepare salsa, combine the first 9 ingredients in a bowl, and toss gently. Cover and chill for 1 hour.
Preheat oven to 425°.
To prepare shortcake, lightly spoon flour into a dry measuring cup; level with a knife. Combine flour and next 4 ingredients (through salt), stirring well with a whisk. Make a well in center of mixture. Combine buttermilk, oil, and egg in a bowl; add to flour mixture. Stir just until moist. Spoon batter into an 8-inch square baking pan coated with cooking spray. Bake at 425° for 20 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 5 minutes on a wire rack. Turn shortcake out onto a cutting board or work surface; cut into 9 equal pieces.
Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add ham to pan, and sauté 1 minute on each side or until lightly browned. Remove from heat; keep warm.
Cut shortcake pieces in half horizontally. Place 1 bottom half on each of 9 plates; top each serving with 1 tablespoon salsa, 1 ham slice, and top half of shortcake. Top each serving with 2 tablespoons salsa. Garnish with cilantro sprigs, if desired.