Combine crumbs, brown sugar and butter to make a crust.
Press into a 9 x 13 cake pan.
Scald milk; mix cornstarch, sugar, salt together, add to milk and bring to a boil.
Add poppy seed and cook on medium for 5 minutes, stirring constantly.
Take a few spoonfuls of this mixture, and add to slightly beaten egg yolks.
Mix together; add egg yolk mixture back into the poppy seed custard mixture, and cook about 5 minutes longer, mixing well until thickened.
Remove from heat and add vanilla.
Cool down a bit and then pour into crust.
Beat reserved egg whites until thick and foamy.
Gradually add 6 T. of sugar beating on high until you can form stiff peaks.
Spread on top of poppy seed custard filling and bake at 325 for 35 to 45 minutes.
Meringue should be light brown.