Mix half-and-half with sugar in top of double boiler; add the vanilla bean; SCALD (this means until the half-and-half forms a film on top of the liquid).
Beat eggs and salt in a large bowl.
Pour a little of the hot half -and-half into beaten egg, stir quickly and pour gradually into hot mixture, stirring constantly, or until the mixture coats spoon.
When thickened, remove abd discard vanilla bean.
Add gelatin and vanilla extract, if you are using only the extract, stir until gelatin is dissolved, then put mixture in blender or use the "Thunder Stick" with blender attachment abd blend until smooth.
Add mascarpone cheese.
Cool about 30 minutes and then add whipped cream.
When cooled about 1 hour, use as any pastry filling, cake filling or pour into lined charlotte mold.
Chill several hours or overnight.
To this recipe you can easily add about 1 - 2 Tablespoon brandy to make the VERY BEST Tiramisu.