Step 1

Heat milk to 170 degrees F.

Step 2

Mix eggs, vanilla, flour, and sugar in a bowl.

Step 3

Slowly add the mixture to the milk and cook until thick and custard-like.

Step 4

Layer the vanilla wafers on the bottom of a baking pan.

Step 5

Slice the bananas and layer over the wafers.

Step 6

Pour the custard over the wafers and bananas. Cool for 1-1/2 hours. Spread the Cool Whip over the top.