Combine peaches and amaretto in a large bowl, tossing gently to coat. Let stand 15 minutes.
While peaches stand, place 2 tablespoons almonds and sugar in a food processor; process 3 minutes or until a paste forms. Add cream cheese and vanilla; process until smooth.
Remove peaches from bowl, reserving amaretto. Place peaches, cut sides down, on grill rack coated with cooking spray; brush peaches with reserved amaretto. Grill 5 to 6 minutes on each side or until tender, basting occasionally with amaretto. Place peach halves on dessert plates; spoon 2 tablespoons almond cream into center of each peach half, and sprinkle evenly with remaining 2 tablespoons almonds. Serve warm.
Note: You may substitute 1/4 teaspoon almond extract plus 3 tablespoons water for the amaretto, if desired.