Boil 2 cups of water in a medium-sized saucepan. Remove from heat and dissolve one package of cranberry Jello in the hot water. Add 1 cup of cold water and refrigerate for about 45 minutes until slightly thickened.

Remove the partially set Jello and whisk in 1 cup of crushed pineapple and 1 cup of 7-Up until evenly combined, keeping some carbonation.

Fold in ½ cup of chopped walnuts, ensuring they are evenly distributed without breaking them up too much.

Pour the mixture into a mold or decorative serving dish, smooth the top, cover with plastic wrap, and refrigerate for at least 3 hours until firmly set.

Run a knife around the edges to loosen the salad, invert onto a platter, slice into squares, and garnish with cranberries or whipped cream if desired.