
4 cups graham cracker crumbs
1½ cups salted butter, melted; divided
1¼ cups granulated sugar, divided
3 large eggs, lightly beaten
1 (15-ounce) can pumpkin
1 (12-ounce) can evaporated milk
2 teaspoons pumpkin pie spice, plus additional for garnish
1 (15.25-ounce) package butter pecan cake mix
⅔ cup chopped pecans, plus additional for garnish
Frozen whipped topping, thawed; for serving