Preheat oven to 350º Fahrenheit. Grease a 9x13 inch baking pan.
Beat eggs, sugar, and spices with an electric mixer in a large bowl until creamy. Add pumpkin puree and evaporated milk and continue to beat until well combined and creamy.
Pour mixture into baking dish and sprinkle with cake mix.
Top with thinly sliced butter, sprinkle with chopped pecans, and bake for 50-55 minutes.