Pumpkin Pudding

1 lg. can pumpkin
1 cup sugar
3 eggs
½ tsp. salt
1 can evaporated milk
4 tsp. pumpkin pie spice
1 pkg. yellow cake mix
1 cube butter
Whipped cream

Mix pumpkin, sugar, eggs, salt, spice, and milk. Spread into greased 9x13 pan. Melt butter and mix with cake mix. Sprinkle over pumpkin mixture. Bake at 350° for 40 min. Serve with whipped cream.