Melt 2 tbsp. butter in large skillet. Add apples and 1/2 cup sugar; stir. Cook on low 15 min. or until sugar is completely dissolved and start turning to caramel, stir occasionally. Add milk and cinnamon; stir. Cook 2 min., remove from heat.
Melt the remaining butter. Add the crumbs (or the buscuits, crushed to crumps) and 2 tbsp. sugar; mix well. Press onto bottoms of 8 paper-lined muffin cups, adding about 1 tbsp. crumb mixture to each cup.
Beat cream cheese, 1/4 cup sour cream and remaining sugar in medium bowl with mixer until blended. Add egg; beat on low speed just until blended. Stir in half the apple mixture. Spoon over crusts.
Preheat oven to 180 C. Bake 20 to 22 min. or until centres are almost set. Cool completely.
Transfer cheesecakes to plate; top with remaining sour cream and apple mixture.