Pre-heat the oven to 350°F.
In large mixer bowl, on low speed, combine the cake mix, 1 egg, margarine/butter and 2 teaspoons of pumpkin pie spice, until crumbly.
Press the mixture onto the bottom of a 15×10-inch jelly roll pan or a Rachael Ray Bubble and Brown Baker.
In large mixer bowl, beat the cheese until fluffy. Gradually beat in the sweetened condensed milk; then the remaining 2 eggs, the pumpkin and the remaining 2 teaspoons pumpkin pie spice and salt; mix well.
Pour over the crust and sprinkle with chopped nuts. Bake for 30-35 minutes, or until set.
Cool. Chill, then into bars. Store in the refrigerator.