This is from my Pie book.
Pre-baked pastry crust
One bag mini Snickers bars, cut in small pieces (about 2 cups)
3/4 c. sugar
3 1/2 tbsp. cornstarch
Big pinch of salt
2 cups whole milk
3 large eggs
1 tbsp. butter
3 tbsp. smooth peanut butter
1 tsp. vanilla
Scatter the Snickers pieces in the pie shell, using enough of them to make a crowded, but not solid, layer. Set aside.
Whisk the sugar, cornstarch and salt together in a medium sized saucepan. Whisk in the milk and egg yolks. Place over medium-high heat and cook, whisking virtually nonstop, until the mixture starts to boil, 5-7 minutes. Continue to cook, whisking nonstop, for 1 to 1 1/2 minutes. Remove from the heat and whisk in the butter, one piece at a time, and the peanut butter, 1 tablespoon at a time. Whisk in the vanilla.
Scoop the filling into the pie shell, covering the Snickers pieces; shake the pie gently to settle filling. Transfer the pie to a wire rack. Press a piece of plastic wrap directly over the filling, leaving no gaps or air pockets, to prevent a skin from forming. When the pie has cooled thoroughly, refrigerate for at least 3 hours or overnight.
Top with whipped cream (the real stuff) and garnish with chopped peanuts, or more candy bars.