1 c. sugar
1/3 c. cornstarch
1/3 c. flour
3 egg yolks
1 1/2 tsp. vanilla
4 c. milk
1 stick butter

Mix flour, sugar, cornstarch in microwave safe bowl. Add milk; stir. Cook on High 3 minutes. Stir. Cook on High another 3 minutes; stir. Add well blended egg yolks. Cook, 1 minute at a time, until thickened. Add vanilla and butter. Blend well. Layer with bananas and vanilla wafers.