1 large can pumpkin (about 30 ounces)
3 eggs lightly beaten
1 can evaporated milk (12 ounces)
1 cup sugar
1 cup chopped pecans
1 box yellow cake mix
2 teaspoons cinnamon
l teaspoon nutmeg
1/2 teaspoon ginger
1 cup melted butter

Preheat oven to 350 degrees. Lightly spray an 9" x 12" pan (size approximate)

Mix together: eggs; sugar; pumpkin; evaporated milk; cinnamon;  nutmeg; and ginger. Pour into pan. 
Top with  the yellow cake mix (as it comes from the box)
Sprinkle 1 cup chopped pecans over cake mix
Drizzle over it melted butter over pecans.  

Bake for 1 hr.