Microwave caramels and milk in microwaveable bowl on HIGH 1-1/2 to 2 min. or until caramels are completely melted, stirring after each minute. Pour into 8-inch round pan sprayed with cooking spray; top with 1/2 cup nuts.
Unroll crescent roll dough; separate into 2 rectangles. Press perforations in each rectangle together to seal. Mix remaining nuts, sugar, cinnamon and raisins; sprinkle over dough. Roll up each rectangle, jelly-roll fashion, starting at one short end; cut into 4 slices. Place, cut sides down, in prepared pan. (Sprinkle with any sugar mixture that may have fallen out of rolls.)
Bake 17 to 20 min. or until lightly browned. Immediately invert pan onto plate; remove pan. Spread any caramel from pan over buns. Cool slightly.