In a saucepan, combine evaporated milk, condensed milk, eggyolks and sifted cornstarch.

Mix until no lumps formed or you can strain the custard mixture if you want.

Cook over low heat, continue stirring until mixtures starts to thicken.

It takes about 8-10 minutes, it depends how thin or thick you want your yema frosting will be.

Fire off, add vanilla extract and butter and stir until well blended.

Let it cool down before using or frosting your cake.