Mix pudding and buttermilk well. Fold in cool whip. Stir in snickers and apples. (Can be made ahead, just put apples in close to serving time so they don't brown.) To make cookie salad: Use 1 can mandarin oranges and 1 can pineapple chunks in place of apples and 1 package fudge stirped cookies, crushed, in place of snickers.