Heat oven to 325º F. With an electric mixer, beat the cream cheese, sugar, and eggs on medium-high until smooth. Mix in 2 cups of the chopped Twix bars. Pour the mixture into the piecrust.
Bake the pie until set, 40 to 45 minutes; let cool.
Sprinkle the pie with the remaining Twix bars and chill until firm, 8 to 10 hours.