In a large microwave-safe bowl, combine the apples, walnuts, raisins, 3 Tbs sugar, flour, 3/4 tsp cinnamon, and salt. Microwave 2-3 minutes or until almost tender.
Flatten each biscuit into a 5 inch circle.Combine remaining sugar and cinnamon; sprinkle a rounded tsp of sugar mixture over each. Top each with 1/4 cup apple mixture. Bring up edges to enclose mixture; pinch edges to seal.
Place seam side down in ungreased muffin cups. Brush tops with butter; sprinkle with remaining sugarmixture. With a sharp knife, cut an "X" in the top of each.
Bake at 350 degrees for 18-22 minutes or until golden brown. Cool for 5 minutes before removing from pan to wire racks.