Preheat oven to 350 degrees. Ignore directions on the cake box mix and place mix in a medium mixing bowl and add 1/2 c. butter. Use your hands to combine the mixture until it looks like dry crumbs. Place half the mixture (about 1 3/4 c.) in an 8×8 inch pan and press into a flat, even layer. Reserve remaining crumbs for later. Combine pumpkin, eggs, sweetened condensed milk, cinnamon, nutmeg, cloves, ginger, and salt in a separate bowl. Whisk until well combined. Pour pumpkin mixture over crumb layer in pan. Add pecans to reserved crumb mixture and sprinkle on top. Melt remaining 4 T. butter and drizzle over crumb topping. Bake 35-45 min. or until top is golden and a knife or skewer inserted in center comes out clean. Top with fresh whipped cream.