Add butter, and mix well.

Press into the bottom and sides of a 9-inch pie pan.

Refrigerate for 15 minutes before filling.

Roll out dough and place into 9-inch pie pan.

If there is more than 1/2 inch of excess over edge, trim crust.

Bake according to directions.

Remember to prick dough with a fork and/or use pie weights to keep crust from puffing up.

Combine sugar and cornstarch in a medium pot.

Gradually whisk in milk, and place over medium heat.

Continue whisking until thickened and bubbly.

Once bubbling, reduce heat and continue to whisk over heat for 2 minutes; remove from heat.

In a small bowl, gently whisk yolks.

Slowly add approximately one cup of milk mixture to yolks while stirring.

Transfer yolk mixture to the pot, return to heat, and bring to a low boil while whisking.

Continue whisking for 2 minutes.

Remove from heat, add butter and vanilla, stirring until combined.

Pour one third of custard into prepared pie crust.

Top with half of sliced bananas.

Spread another third of the custard over the banana slices.

Top custard with remaining banana slices.

Spread remaining third of custard on bananas.

Cover with plastic wrap and refrigerate for at least 2 hours.